F 


n 
o 


T1 
Ul 


C 
en 
a) 


BANCROFT 

LIBRARY 

<• 

THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 


LIBRARY 
Tf         O  Oe-PoprCtcJ    r 

V*V   »        x*  IT*  C  Ci 


PRELIMINARY    REPOR/T 


OF  THE 

FIELD-WORK  OF  THE  UNITED  STATES  GEOLOGICAL  AND  GEO- 
GRAPHICAL SURVEY  OF  THE  TERRITORIES, 

UNDER  THE  DIRECTION  OF  PROF.  F.  V.  HAYDEN, 

FOR   THE   SEASON  OF   1877.        — 


OFFICE  OF  THE  UNITED  STATES  GEOLOGICAL  AND 

GEOGRAPHICAL  SURVEY  OF  THE  TERRITORIES, 

Washington,  D.  0.,  December  1,  1877. 

SIR:  I  have  the  honor  to  submit  the  following  preliminary  report  on 
the  operations  in  the  field  of  the  Survey  under  my  charge  during  the 
season  of  1877. 

On  the  completion  of  the  survey  of  Colorado  last  year,  it  was  deter- 
-^  mined  that  the  work  of  the  United  States  Geological  and  Geographical 
Survey  of  the  Territories  under  my  direction  should  continue  north- 
ward into  Wyoming  and  Idaho.  The  belt  of  country  including  the 
Pacific  Railroad  having  been  explored  and  mapped  in  detail  by  the 
Survey  of  the  Fortieth  Parallel,  under  Clarence  King,  esq.,  it  was  deemed 
best  to  commence  at  the  northern  line  of  that  work,  and  continue  north- 
ward and  westward,  taking  for  the  season  of  1877  the  country  from  Fort 
Steele,  Wyoming  Territory,  to  Ogden,  Utah,  or,  more  exactly,  from  longi- 
tude 107°  to  112°,  and  northward  to  the  Yellowstone  Park. 

The  primary-triangulation  party,  in  charge  of  Mr.  A.  D.  \Vilsou, 

Chief  Topographer  of  the  Survey,  took  the  field  from  Rawlins  Springs, 

Wyo.    Near  this  point  a  base  line  was  measured  with  great  accuracy, 

Q   from  which  a  net- work  of  triangles  was  extended  over  the  country  to 

O   the  north  and  west,  locating,  at  intervals  of  from  twenty  to  thirty  miles, 

some  prominent  peaks,  upon  which  stone  monuments  were  built,  in  order 

^  that  the  topographers  could  recognize  the  points  thus  fixed  for  them. 

:  Upon  these  points  was  based  the  system  of  secondary  triangulation. 

From  the  base  at  Rawlins,  the  work  was  carried  northward  to  the 
ui  Sweet-water  Mountains,  and  thence  to  the  Wind  River  Range.     Upon 
^5  some  of  the  more  prominent  peaks  of  the  latter  range,  such  as  Fremont's 
*"  Peak,  the  stations  were  made  with  much  difficulty,  owing  to  the  great 
masses  of  snow  found  there  during  the  mouth  of  June,  when  the  party 
was  working.     From  this  range  the  work  was  carried  across  the  Green 
River  Basin  to  the  mountains  on  the  west  and  north,  where  several 
stations  were  made.    The  work  was  resumed  to  the  west  as  far  as 
i^ort  Hall,  Idaho,  and  thence  south  to  the  vicinity  of  Bear  Lake,  where 
another  base,  or  base  of  verification,  was  measured  ;  thence  south  as  far 
as  Ogden  and  Evanston,  connecting  with  the  triaugulatiou  of  the  Forti- 
eth Parallel  Survey  at  these  points.   From  Evanston  the  party  marched 
eastward,  making  some  stations  north  of  the  railroad,  thus  bringing  the   f 
work  back  to  the  point  of  beginning,  Rawlins  Springs,  where  the  party  v. 


was  disbanded  for  the  season.    The  system  of  triangulation  employed 


756     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

during  the  past  season  was  essentially  tbe  same  as  that  carried  over 
Colorado.  , 

The  n  humiliation  is  all-important,  as  the  topographical  work  depends 
entirely  upon  it,  and  the  geologist  can  do  but  little  without  an  accurate 
map.  'Tnns  the  topographical  as  well  as  the  geological  maps  are  de- 
piMidtMit  upon  a  good  system  of  primary  triangulation. 

In  addition  to  the  primary-triangulation  party  already  referred  to, 
there  were  three  fully  equipped  divisions  for  topographical  and  geolog- 
ical work,  and  another,  under  the  direction  of  Dr.  0.  A.  White,  tor  crit- 
ical paheoutological  work. 

The  area  assigned  to  the  Green  Kiver  division,  under  the  direction  of 
31  r.  Henry  Gannett,  was  rectangle  No.  56,  which  is  limited  on  the  east 
and  west  by  the  meridiausof  109°  30' and  112°  and  on  the  north  and  south 
by  the  parallels  of  43°  and  41°  45'.  This  is  an  area  of  about  11,000  square 
miles,  lying  in  parts  of  Wyoming,  Utah,  and  Idaho.  The  party  took  the 
Held  at  Green  River  City,  Wyo.,  on  June  1.  They  first  surveyed 
the  drainage  of  Green  Eiver  Basin.  For  this  purpose  they  traveled  up 
the  Big  Sandy,  a  large  eastern  branch  of  the  Green,  to  the  foot  of  the 
Wind  Kiver  Mountains  ;  thence  crossing  the  head  of  the  basin,  fording 
the  large  and  rapidly  rising  streams  which  make  up  the  New  Fork  of  the 
Green,  they  reached"  the  main  Green,  and  traveled  down  its  western 
bank,  going  in  to  Granger,  Wyo.,  on  the  Union  Pacific  Kailroad,  for 
supplies  on  June  23. 

The  Green  Kiver  Basin  is  a  broad,  flat,  almost  unbroken  expanse, 
covered  mainly  with  sage,  among  which  considerable  grass  is  scattered. 
Its  greatest  width  in  this  district  is  about  50  miles,  and  its  length  reaches 
nearly  a  hundred.  Its  area  within  the  district  is  not  far  from  3,000 
square  miles. 

The  river-bottoms  of  the  Green  and  its  branches,  excepting  the  Big 
Sandy,  are  everywhere  broad  and  beautiful,  well  covered  with  grasses, 
and  shaded  by  magnificent  groves  of  cottonwood.  For  agricultural 
purposes  these  bottom-lands  are  very  valuable,  while  the  limitless  ex- 
panse of  bunch-laud  would  afford  grazing  to  enormous  herds  of  cattle. 
The  Big  Sandy  is  in  low  canon  through  most  of  its  course. 

Leaving  Granger,  the  party  next  surveyed  the  broken,  hilly  country 
lying  between  the  basin  and  the  upper  course  of  Bear  River,  north  of 
Ilariis's  Fork.  Following  this  belt  northward,  these  hills  develop  into 
mountains  of  considerable  importance  about  those  large  branches  of  the 
Snake  known  as  John  Day's  and  Salt  Rivers.  The  party  surveyed  this 
belt  northward  to  the  north  line,  whence,  turning  westward,  they  mapped 
the  basin  ol  the  Blackfoot  and  the  valleys  of  the  Portneuf;  thence  going 
in  to  Fort  Hall,  early  in  August,  for  further  supplies  of  provisions. 
Taking  up  this  section  of  the  district  in  the  order  in  which  it  was  worked, 
it  will  be  noud  that  the  valley  of  Harris's  Fork  is  fine  agricultural  land; 
that  the  hills  about  its  head,  separating  it  from  the  Bear,  are  rounded 
and  gia>s  covered,  affording  a  magnificent  stock-range.  As  the  hills  in- 
crease in  si/e  and  assume  the  dignity  of  mountains,  the  grass  gives 
j  lace  to  heavy  pine  and  spruce  timber  of  fine  quality.  John  Day's  Kiver 
tlows  in  a  canon  valley,  heavily  timbered.  The  valley  of  Salt  Kiver  is 
nearly  ten  miles  in  width  and  of  the  finest  quality  of  land.  West  of 
this  valley  are  high,  broken  hills,  separating  Salt  Kiver  from  the  Black 
loot.  The  latter  stream  pursues  a  devious  course  in  a  great  plain  of 
basalt,  diversified  by  buttesand  extinct  craters.  Along  the  river  are  fine 
meadows,  alternating  with  large  swamps.  The  whole  basin  is  covered 
with  the  best  of  grass. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       757 

West  of  this  basin  the  Black  foot  is  separated  from  tbe  Portneuf,  here 
flowing  south,  by  a  range  of  low,  grass-covered  hills.  The  valley  of  the 
Upper  Portneuf  is  at  least  eight  miles  broad,  and  is  valuable  for  agri- 
culture or  grazing.  West  of  it  is  a  high  range  of  mountains,  through 
which,  lower  down,  the  Portneuf  cuts  its  way  into  another  broad  valley, 
in  which  it  flows  to  the  north.  This  valley  is  floored  with  basalt,  and 
is  almost  valueless. 

From  Fort  Hall  the  party  proceeded  to  survey  the  country  drained  by 
the  Bear  and  its  tributaries,  proceeding  generally  from  the  east  west- 
ward. The  country  is  a  succession  of  parallel  valleys,  separated  by 
ranges  of  bare,  grass-covered  hills  or  timbered  mountains.  The  most 
eastern  of  these  valleys  is  on  the  upper  waters  of  the  Bear.  It  is  nearly 
ten  miles  wide,  of  good  soil,  and  easily  irrigated.  The  only  drawback  to 
agricultural  pursuits  is  the  elevation,  6,000  to  6,500  feet,  which,  in  this 
latitude,  indicates  severe  winters. 

Kext  westward  is  Bear  Lake  Valley.  Here  the  cultivable  area  is  at 
the  head  and  foot  of  the  lake,  besides  a  narrow  strip  on  its  west  border. 
Below  the  lake,  the  valley  extends  on  to  the  northward  for  many  miles 
down  the  Bear,  and  is  very  broad  and  fertile.  The  elevation  of  this  val- 
ley is  5,500  to  6,000  feet. 

Further  westward  we  encounter  the  Bear  River  Range,  a  broad  belt 
of  mountains  reaching  nearly  to  10,000  feet  in  height,  and  heavily  tim- 
bered. Beyond  is  Cache  Valley,  one  of  the  finest  arens  of  farming-land 
west  of  the  Missouri.  The  elevation  is  4,500  to  5,000  feet.  Besides 
grain,  nearly  all  garden-vegetables  and  many  fruits  are  raised  in  this 
valley. 

A  broken  range  of  mountains  separates  this  valley  from  that  of  the 
Malade.  The  latter  has  about  the  same  elevation  as  Cache  Valley,  and 
is  almost  equally  fine.  Beyond  it  is  a  range  of  grass-covered  hills,  sep- 
arating it  from  Blue  Creek  Valley. 

The  valleys  of  the  Bear  are  peopled  mainly  by  Mormons;  very  few 
Gentiles  indeed  are  to  be  found  there.  Mormon  settlements,  of  greater 
or  less  extent,  are  to  be  found  all  along  the  Bear,  from  its  mouth  nearly  to 
Randolph.  Malade  Valley  is  but  sparsely  settled  as  yet.  Cache  Valley 
contains  several  good-sized  towns ;  the  eastern  part  of  the  valley  is  quite 
closely  settled.  The  valley  of  Bear  Lake  contains  several  good-sized 
towns,  but  above  that  settlements  are  scarce. 

The  party  left  the  field  at  Ogden,  Utah,  on  September  30,  having  been 
in  the  field  just  four  months.  The  area  surveyed  was  between  12,000 
and  13,000  square  miles ;  347  stations  and  locations  were  made ;  53  of 
the  stations,  being  important  ones,  were  marked  with  stone  monuments 
for  future  reference. 

The  geological  work  of  Dr.  A.  C.  Peale  in  the  Green  River  district  con- 
nected directly  with  the  eastern  edge  of  the  Sweetwater  district. 

With  the  exception  of  a  small  area  of  granite  along  the  southwestern 
side  of  the  Wind  River  Mountains,  and  some  basaltic  flows  in  the  north- 
western portion  of  the  district,  the  rocks  are  sedimentary,  including  the 
rocks  from  the  Carboniferous  to  very  late  Tertiary  age. 

The  first  month  of  the  season  was  occupied  mainly  with  the  survey  of 
the  Green  River  Basin.  Leaving  Green  River  City,  the  river  was  fol- 
lowed to  the  mouth  of  the  Big  Sandy,  a  shallow,  muddy  stream,  rising 
in  the  southwestern  slopes  of  the  Wind  River  Mountains.  Both  on  Green 
River  and  the  Big  Sandy  the  prevailing  formation  is  the  Green  River 
Tertiary  group,  consisting  of  clays,  marls,  and  calcareous  sandstones, 
forming  blufls  on  the  rivers.  These  [strata  continue  uninterruptedly 


758     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

westward,  inclining  eastward  from  the  bills  west  of  Green  River.  To- 
\\anl  tin-  southern  part  of  the  district  remains  of  the  Bridger  clays  are 
n,  t -.rniing  Imttes  on  the  Green  River  beds.  They  are  the  outlines 
of 'tiii'  extensive  Bridger  areas  that  extend  southward.  On  the  south- 
west slopes  of  the  Wind  River  Mountains  there  are  abundant  evidences 
of  comparatively  recent  glacial  action. 

The  next  area  taken  up  was  that  lying  between  Green  River  and  the 
Hear,  \vith  a  strip  along  the  northern  edge  of  the  district,  reaching  west- 
ward beyond  Fort  Hall. 

The  mountains  west  of  Green  River  are  composed  mainly  of  Carbonif- 
erous limestones.  Toward  the  north  they  form  two  beautiful  ranges  on 
John  Day's  River  and  Salt  River,  separated  by  a  valley  in  which  rocks 
of  Jurassic  and  Cretaceous  age  outcrop.  Between  the  mountains  and 
the  Green  River  Basin  is  a  range  of  hills  of  Jurassic  and  Cretaceous 
a.ue.  On  the  east  of  these  is  the  Wasatch  group  of  Tertiary,  resting 
tineon tonnably  on  the  Jurassic  hills.  Farther  north  the  Wasatch  beds 
cover  the  Jurassic  and  Lower  Cretaceous  strata,  extending  partly  over 
the  Laramie  Cretaceous,  with  which  it  is  u  neon  form  able.  Carbonifer- 
ous fossils  were  obtained  from  limestone  bowlders  in  a  conglomerate  at, 
the  base  of  the  Wasatch.  These  were  derived,  without  doubt,  from  the 
Carboniferous  mountains  to  the  westward,  which  formed  the  shore-line 
of  the  ancient  lakes  in  which  these  beds  were  deposited.  An  arm  of 
this  lake  extended  up  Harris's  Fork  of  Green  River.  The  Green  River 
and  Wasatch  beds  here  are  horizontal,  the  former  containing  abundant 
remains  of  insects  and  fish.  Good  collections  were  obtained  at  several 
localities. 

The  region  of  the  Blackfoot  River,  in  the  northern  portion  of  the  dis- 
trict, is  covered  in  the  lowest  portions  with  flows  of  basalt.  These  had 
their  origin  between  the  Blackfoot,  Bear,  and  Portneuf  Rivers.  A 
number  of  the  craters  still  remain.  One  of  these,  south  of  the  Black- 
foot,  is  very  distinct,  rising  200  feet  above  the  general  level.  It  is 
about  130  yards  in  diameter,  and  has  a  circular  depression  on  the  sum- 
mit. The  pouring  out  of  this  basalt  must  have  occurred  either  during 
or  immediately  prior  to  our  present  period,  as  there  has  been  little  if 
any  change  in  the  surface  since  the  eruption. 

The  Blackfoot,  Portneuf,  and  Bear  all  have  the  basalt  in  their  val- 
leys. Cu  the  Portneuf  it  extends  almost  to  the  Snake  River  plain, 
showing  as  a  narrow  belt.  Its  surface  slopes,  but  not  so  much  as  the 
present  bed  of  the  stream.  In  some  places  the  volcanic  rock  appears  to 
have  pushed  the  river  to  the  western  side  of  the  valley.  The  lower  val- 
ley of  the  Portneuf  is  interesting  from  the  fact  that  it  is  the  probable 
ancient  outlet  of  the  great  lake  that  once  filled  the  Salt  Lake  Basin.  At 
the  head  of  Marsh  Creek,  which  occupies  the  valley,  continuing  directly 
south  from  that  of  the  Lower  Portueuf,  is  the  lowest  pass  between  the 
Great  Basin  and  the  drainage  of  the  Columbia.  In  fact,  so  low  and 
flat  is  it  that  a  marsh  directly  connects  the  two  streams,  one  flowing  to 
the  Bear  and  the  other  to  the  Portneuf  and  Snake  Rivers. 

The  bend  of  Bear  River  at  Soda  Springs  is  one  of  the  most  remarkable 
features  of  the  whole  district.  Rising  in  the  Uintah  Mountains,  Bear 
Kiver  Hows  northward  for  over  two  hundred  miles,  and  at  Soda  Springs 
bends  abruptly  and  flows  southward  toward  Salt  Lake.  After  it  emerges 
from  the  <;a|,  west  of  Soda  Springs,  it  flows  out  into  a  wide  valley  which 
opens  directly  into  that  of  the  Upper  Portuenf.  In  this  valley  the  divide 
between  the  two  rivers  is  only  a  basalt  plain,  and  in  the  eruption  of 
tins  lava  we  may  look  for  the  clew  to  the  extraordinary  course  of  Bear 
River. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       759 

Forth  of  the  bend  of  Bear  River  the  mountains  consist  of  isolated 
masses  of  Jurassic  and  Carboniferous  rocks,  the  general  strike  of  the  rocks 
being  northwest  and  southeast.  There  are  several  interesting  folds  in 
the  rocks  of  this  region. 

The  interesting  springs  at  Soda  Springs  were  carefully  examined. 

The  latter  half  of  the  season  was  devoted  to  Bear  River,  Bear  Lake, 
and  Cache  and  Malade  Valleys. 

The  Upper  Bear  River  Valley  has  a  wide  drift-covered  bottom.  The 
hills  on  the  east  side  soon  develop  into  mountains  as  we  go  north.  Forma- 
tions from  the  Carboniferous  up  to  the  Wasatch  Tertiary  are  represented, 
the  latter  resting  on  the  upturned  edges  of  the  older  rocks.  On  the  west 
the  same  unconformability  is  seen,  the  area  of  Wasatch  extending 
farther  north.  The  beds  consist  of  variegated  sandstones  and  conglom- 
erates. Bear  Lake  Valley  has  a  range  of  low  hills  on  the  east,  at  the 
foot  of  which  the  lake  leaves  but  a  narrow  margin.  The  waters  of  the 
lake  occupy  an  area  that  is  probably  underlaid  by  several  folds. 

The  Bear  River  Mountains  are  composed  of  Silurian  and  Carbonifer- 
ous rocks,  limestones,  and  quartzites.  The  edges  of  the  strata  face  the 
east,  but  as  \ve  go  west  we  soon  cross  a  synclinal  fold,  the  western  side 
of  which  rises  into  high  peaks  on  the  east  side  of  Cache  Valley.  The 
base  of  the  range  facing  Cache  Valley  is  Silurian.  It  is  abrupt,  and  the 
basset  edges  of  the  strata  give  it  extreme  raggedness.  In  the  canons 
of  the  streams  coming  from  the  range,  saw-mills  have  been  erected,  and 
now  supply  the  flourishing  towns  of  the  valley.  Numerous  lime-kilns 
also  furnish  them  with  a  good  quality  of  lime,  the  limestone  being  derived 
from  the  adjacent  rocks. 

There  is  but  little  doubt  that  the  waters  which  once  filled  the  Salt  Lake 
Basin  covered  also  the  broad  Cache  Valley.  The  modern  Tertiary  deposits 
are  found  jutting  against  the  mountains,  and  seem  to  pass  gradually  into 
the  more  recent  deposits  found  in  the  central  portion  of  the  valley.  The 
clays,  sands,  and  marls  of  these  modern  beds  are  beautifully  exposed 
along  Bear  River,  which  cuts  its  way  across  the  northwestern  part  of 
the  valley.  On  the  west  the  mountains  are  broken  or  isolated  ranges, 
which  seem  to  have  risen  above  the  waters  of  the  old  lake  as  islands. 
The  terraces  are  well  marked  on  their  sides,  connecting  with  the  Salt 
Lake  Valley  through  the  gap  of  Bear  River. 

West  of  this  gap,  and  extending  northward,  is  the  Malade  Valley.  It 
is  broid  and  filled  with  modern  lake  deposits.  Silurian  rocks  outcrop 
on  the  east  and  Carboniferous  on  the  west.  At  the  divide  between  the 
Malade  and  Marsh  Creek  is  another  of  the  old  outlets  of  the  ancient  Salt 
Lake  when  its  waters  were  at  the  highest  level.  Although  the  area  sur- 
veyed was  large,  (13,000  square  miles,)  good  collections  of  fossils  were 
made  and  data  obtained  for  the  elucidation  of  many  interesting  prob- 
lems in  relation  to  the  age  of  the  mountains.  The  entire  district  is 
of  great  interest  to  the  geologist.  Coal-outcrops  were  noted  at  a  num- 
ber of  places  on  the  Upper  Bear  River  and  its  tributaries,  and  on  some 
of  the  branches  of  Green  River. 

At  one  locality  between  Twin  Creek,  a  branch  of  the  Bear,  and  Harris's 
Fork,  a  tributary  of  Green  River,  there  are  some  twenty-nine  coal  beds, 
separated  by  sandstones  and  clays,  the  aggregate  thickness  being  315 
feet.  The  beds  of  coal  are  from  1  foot  to  48  feet  thick.  This  locality 
has  been  called  the  "  Mammoth  Vein." 

The  area  allotted  for  examination  to  the  Sweetwater  division,  under 
the  direction  of  Mr.  G.  B.  Chittenden,  covering  atlas-sheet  No.  57,  ,is 
bounded  on  the  east  by  the  meridian  107°,  and  on  the  west  by  that  of 


7 GO     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

1000  30'  of  west  longitude,  and  on  tbe  north  by  the  parallel  of  41°  45', 
iiiul  on  the  south  by  that  of  43°  of  north  latitude,  embracing  a  district 
of  ;il)out  10.SUO  square  miles. 

In  working  this  area,  171  principal  topographical  stations  were  made, 
U-xuirs  sonic  twenty  auxiliary  ones  not  numbereJ  in  the  regular  series. 
Between  eighty  and  ninety  stone  monuments  were  erected  on  these 
stations  to  mark  them  permanently,  while  the  peculiar  topographical 
features  of  a  great  many  others  mark  them  with  equal  distinctness. 
While  many  of  these,  owing  to  the  extremely  desolated  character  of  the 
country  surveyed,  are  not  likely  ever  to  be  used  as  initial  points  for  the 
rectilinear  surveys,  there  still  will  be  many  others  which  will  be  of  very 
great  value  in  giving  starting-points  for  isolated  pieces  of  rectilinear 
work,  where  fertile  valleys  and  oases  in  this  desert  country  are  rapidly 
coming  into  demand  by  the  settler.  The  most  important  of  these  fertile 
tracts  are  on  the  great  southern  drainage  of  the  Wind  River;  the  whole 
of  the  Sweetwater,  with  its  southern  tributaries;  Sand  Creek:  the 
drainage  of  the  old  Seminole  mining-district,  and  a  series  of  lakes  and 
springs  south  of  the  Sweetwater,  near  the  latitude  of  Saint  Mary's 
Station. 

Into  the  first  two  of  these  districts  (or  a  portion  of  them)  a  rectilinear 
survey  was  pushed  this  season  by  the  measuring  of  a  guide-meridian 
from  the  railroad,  north,  and  the  establishment  of  base-lines  within 
the  district.  The  guide-meridian  had  to  be  measured  over  about  seven- 
ty-five miles  of  broken  desert  country,  where  water  was  extremely  scarce 
and  found  only  at  long  intervals.  In  the  vicinity  of  all  these  fertile  dis- 
tricts, particular  pains  were  taken  to  give  permanent  markings  to  the 
topographical  stations,  and  connections  were  made  on  two  of  the  guide- 
meridian  stakes,  distant  some  forty  miles  from  each  other. 

In  continuance  of  the  summer's  work,  the  party  took  the  field  from 
Salt  Wells  Station,  on  the  Union  Pacific  Railroad,  on  the  1st  day  of 
June,  and  completed  tbe  topographical  work  on  the  25th  day  of  Septem- 
ber, in  the  vicinity  of  Fort  Steele.  Owing  to  orders,  received  at  the 
beginning  of  the  season,  to  complete  the  field-work  by  the  1st  of  Octo- 
ber, and  the  very  doubtful  safety  of  a  tract  of  low  country  in  the  north- 
eastern portion  of  the  district,  an  area  of  about  800  square  miles  was 
necessarily  left  unworked  in  that  portion  of  the  district.  The  total 
area  worked  by  the  party,  as  nearly  as  can  be  estimated  before  the  final 
plat  is  made,  was  10,000  square  miles.  Careful  notes  were  made  on  the 
grazing  facilities,  timber,  and  irrigability  of  the  whole  district,  which 
will  be  more,  fully  given  in  a  later  report.  Taken  in  masses,  an  estimate 
of  this  area  shows  five-eighths  to  be  desert  country,  two-eighths  mount- 
ainous, and  the  remaining  eighth  valuable  laud.  "Giving  these  figures 
before  the  plat  is  made,  they  are  of  course  merely  estimates,  but  will 
afford  an  idea  of  the  general  characteristics  of  the  country. 

The  weather  throughout  the  entire  season  was  much  colder  than  that 
experienced  at  thesame  altitudes  in  Colorado,  buttheparty  suffered  much 
less  from  rain,  and  in  the  four  months  of  field-work  did  not  lose  one 
single  day  from  bad  weather,  or  indeed  from  any  cause. 

Dr.  F.  M.  Endlich,  Geologist  of  the  Sweetwater  division,  states  that 
within  the  area  described  above  he  found  a  well  diversified  country. 

A  portion  of  the  Wind  River  Mountains,  in  the  northwest  coruer'-'the 
Sweetwater  and  Seminole  Hills,  toward  the  eastward,  in  ad  litiou  to  the 
lower  bluff-country  in  the  southern  portion,  furnished  material  at  once 
lull  ot  interest  to  the  student  and  to  the  surveyor. 

After  having  surveyed  fhat  portion  of  the  Green  River  drainage  which 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       761 

lies  immediately  outside  of  the  mountains,  the  first  halt  was  made  at 
Camp  Stambaugh.  The  party  until  then  had  passed  through  a  region 
containing  none  but  Tertiary  formations.  But  little  variation  was 
found  in  the  arrangement  of  strata,  as  well  as  in  the  distribution  of  fossil 
remains.  Isolated  volcanic  eruptions  of  small  dimensions  produced 
prominent  bluffs,  far  visible.  These  formed  excellent  landmarks,  and 
were  duly  utilized  as  such.  From  Stambaugh,  the  party  turned  its 
course  southward  toward  the  Union  Pacific  Railroad.  Here,  too,  the 
regular  succession  of  Tertiary  strata  prevailed.  The  readily-disintegrat- 
ing sandstones  of  the  region  have  given  rise  to  the  formation  of  very 
extensive  sand  dunes.  It  may  be  observed  that  westerly  winds  are 
prevalent  throughout  that  section  of  country,  and,  as  the  result  thereof, 
we  find  them  driving  the  sand  to  leeward  and  depositing  it  wherever 
the  configuration  of  the  country  presents  any  obstacle  to  its  farther  prog- 
ress. In  this  manner  a  "belt"  of  sand-dunes,  about  ten  miles  wide  and 
fifty  miles  long,  has  been  formed.  Some  difficulty  was  here  experienced, 
occasioned  by  the  sparing  distribution  of  water.  Only  in  springs  and 
small  alkaline  lakes  could  it  be  obtained. 

lied  Desert  Siation,  on  the  Union  Pacific  Railroad,  was  the  point 
reached  June  18.  From  there  the  party  moved  northward  again  toward 
Stambaugh,  which  place  was  reached  July  3.  Stambaugh  is  located 
within  the  area  of  the  oldest  metamorphic  rocks  of  the  district.  In  these 
metamorphics  gold  has  been  found  during  the  last  ten  years  in  varying 
quantities,  and  the  region  was  at  one  time  the  scene  of  considerable 
mining  excitement.  At  present  the  mines  have  been  to  a  great  extent 
abandoned,  and  but  little  activity  is  noticeable. 

Snow  still  covered  a  large  portion  of  the  Wind  River  Mountains,  and 
it  was  deemed  advisable,  therefore,  to  carry  on  the  explorations  in  some 
lower  country  until,  late  in  the  season,  the  mountains  should  be  more 
accessible. 

On  July  5  the  party  left  Stambaugh  and  marched  toward  the  low 
valleys  belonging  to  the  Wind  River  drainage.  The  difference  in  ele- 
vation amounted  to  about  3,000  feet,  and  the  temperature  of  the  atmos- 
phere was  consequently  much  higher.  While  all  the  surroundings  of 
the  post  were  totally  useless  for  agricultural  purposes,  the  valleys  of  the 
Popo-Agies  and  their  tributaries  contained  excellent  farming  land.  In 
spite  ot  continually  threatened  raids  by  the  Indians,  a  large  number  of 
settlers  have  taken  advantage  of  the  good  soil  and  mild  climate.  With 
the  change  of  elevation  the  geological  formations  change,  instead  of 
the  youngest  beds  resting  directly  upon  the  metamorphics,  we  now  find 
a  full  series  of  the  sedimentary  formations,  beginning  with  the  Silurian. 
Numerous  interesting  stratigraphical  phenomena  were  observed  and 
studied  with  a  view  to  determine  their  relations  to  the  main  mountain- 
chain.  An  ample  amount  of  evidence  has  been  obtained,  more  particu- 
larly by  this  means,  to  speak  positively  respecting  the  geological  age  of 
the  Wind  River  Mountains.  These  latter,  in  this  region,  furm  the  main 
Rocky  Mountain  chain,  and  the  determination  of  their  age  will  neces- 
sarily throw  much  light  upon  the  same  question  arising  in  other  por- 
tions ot  the  same  range.  It  will  be  possible  to  speak  with  a  certain 
degree  of  precision  of  either  the  local,  varying  (as  to  time)  elevation 
of  the  mountains  or  to  refer  it  to  one  particular  epoch  for  the  distance 
of  many  hundreds  of  miles. 

Camp  Brown  is  located  in  the  valley  of  the  Little  Wind  River,  which 
there  is  of  considerable  breadth.  The  famous  hot  springs  there  were 
examined.  As  the  main  peaks  of  the  Wind  River  Mountains  were 
mostly  inaccessible  from  the  east  side,  it  was  deemed  advisable  to  make 


762  REPORT   OF    THE    SECRETARY    OF    THE    INTERIOR. 

the  ascents  of  the  highest  from  the  west.  Therefore  the  party  traveled 
along  tin*  eastern  foot  hills,  through  a  very  ragged  country,  until  Stam- 
baugh  was  reached. 

July  22  the  party  again  left  Stambaugh  and  marched  along  the  head- 
water's first  of  Sweetwater  River  and  then  of  the  eastern  tributaries  of 
Green  Kiver.  Several  of  the  highest  peaks  were  ascended,  and  the 
greatest  altitude  reached  found  to  be  about  13,700  feet.  This  latter  was 
iin  what  the  settlers  generally  designate  as  Fremont's  Peak.  From 
careful  comparison  of  Fremont's  report  with  the  observations  made  by 
the  party,  it  is  evident  that  a  misapplication  of  the  name  has  been 
made,  and  that  the  peak  in  question  is  not  the  one  ascended  by  that 
intrepid  explorer  of  an  "early  day." 

Having  reached  the  northern  limit  of  the  district,  the  route  was  re- 
versed and  the  western  foot-hills  of  the  main  ranges  examined.  Here,  as 
well  as  in  the  mountains  proper,  were  noticed  the  remains  of  enormous 
ancient  glaciers.  Moraines,  covering  many  square  miles,  often  a  thou- 
sand feet  in  thickness,  extend  downward  through  narrow  valleys,  now 
containing  rushing  streams.  Striation,  grooving,  and  mirror-like  polish 
of  rock  in-  situ  denote  the  course  taken  by  the  moving  ice-fields  that 
have  left  these  marks  of  their  former  existence.  From  all  appearance 
the  cessation  of  glacial  activity  must  have  occurred  within  a  compara- 
tively recent  time.  Scarcely  any  vegetation  has  sprung  up  on  the  light 
glacial  soil,  and  the  characteristic  distribution  of  erratic  material  bears 
every  evidence  of  u freshness.7'  Considering  the  enormous  amount  of 
snow  and  ice  that  was  observed  by  the  party  exploring,  (latter  part  of 
July  and  beginning  of  August,)  the  view  was  expressed  by  the  geolo- 
gist that  the  discovery  of  still  active  glaciers  in  that  range  would  by 
110  means  be  surprising. 

Returning  for  the  last  time  to  Stambaugh,  the  route  was  taken  in  an 
easterly  direction  along  the  Sweetwater  and  its  drainage.  First,  the 
adjacent  drainage  of  the  Wind  River  was  surveyed,  and  the  divide  be- 
tween the  two  streams  crossed.  All  along  the  Sweetwater  the  charac- 
teristic "  Sweetwater  group  "  of  Tertiary  age  was  found  to  occur.  It 
has  been  named  and  described  in  my  former  publications.  This  con- 
tinued uninterruptedly  until  a  series  of  hills  north  of  the  river,  oppo- 
site Seminole  Pass,  was  reached.  These  consist  merely  in  projections 
of  granite  that  during  the  Tertiary  epoch,  and  probably  long  before 
that,  had  remained  as  islands  above  a  widely-extended  sea.  Apart 
from  their  singularly  unique  character  in  this  respect,  the  granite  it- 
self possesses  a  peculiarity  that  renders  it  at  once  conspicuous.  Ow- 
ing to  the  distribution  of  component  minerals,  this  granite  is  in  a  high 
degree  subject  to  exfoliation.  Probably  the  main  cause  of  this  may 
be  found  in  the  action  of  freezing  water.  The  result  is  striking.  In- 
stead of  the  rugged  outlines  usually  presented  by  isolated  granitic  out- 
crops, we  lind  a  series  of  rounded,  smooth,  almost  totally  barren  hills. 
To  such  an  extent  is  this  feature  developed  that  many  of  them  offer 
serious  obstacles  to  ascent.  A  locality  where  the  celebrated  moss-agates 
occurred  in  great  quantities  was  found  in  that  region,  and  the  geognostic 
horizon  of  these  interesting  quartz  varieties  was  established.  Marching 
southward,  the  party  crossed  the  Sweetwater,  and  in  the  Seminole  Hills 
once  more  encountered  older  sedimentary  formations.  Disturbances 
<>t  enormous  dimensions  have  here  taken  place,  and  render  the  study 
of  the  range  one  of  extreme  interest. 

On  AuguM  _M)  Uawlins  was  reached  and  the  provisions  for  the  folio  w- 
ng  month  taken.  From  there  the  course  lav  northward,  through  low 
dry  country,  where  several  alkali-lakes  furnished  water.  Between  two 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       763 

• 

of  these,  a  short  distance  apart  only,  a  rare  occurrence  was  observed. 
Mud-springs,  analogous  to  the  mud-puffs  of  the  famous  Geyser  region, 
covered  about  two  square  miles.  Some  of  them  were  extinct,  but 
most  of  them  were  still  in  action.  By  some  force,  which  will  not  be 
here  discussed,  the  water  is  caused  to  enter  cylindrical  orifices  of  vary- 
ing dimensions.  Inasmuch  as  th,is  water  contains  in  solution  a  large 
amount  of  mineral  substances,  and  there  is  suspended  in  it  a  very  large 
quantity  of  tine  clay,  evaporation  produces  a  deposition  of  these  mate- 
rials. In  this  manner  a  cone  is  gradually  raised,  consisting  of  slightly 
arenaceous  clay.  So  long  as  the  force  acting  upon  the  water  is  more 
than  adequate  to  the  height  of  the  cone,  there  will  remain  a  circular 
opening  at  the  top  of  the  latter.  When,  however,  this  ceases,  the  result 
is  simply  a  mound.  About  four  hundred  of  these  curious  springs  were 
found  and  examined.  Great  care  was  requisite,  as  the  soil  is  very 
treacherous,  and  a  mud-bath  inevitable  in  case  of  breaking  through. 

The  Sweetwater  and  Seminole  Hills  were  examined  during  this  trip 
and  found  to  afford  ample  material  for  study.  Stratigraphically  consid- 
ered, they  may  be  regarded  as  being  among  the  most  interesting  portions1 
of  the  district.  A  satisfactory  distribution  of  fossils  in  the  various 
formations  permitted  all  difficulties  to  be  readily  interpreted. 

September  17,  Dr.  Endlich  left  the  party  and  proceeded  to  examine 
the  coal-bearing  series  and  the  mines  near  Evanston,  Wyo.  This 
was  done  with  a  view  to  present  at  an  early  date  a  report  upon  a  sub- 
ject which  now  has  become  one  of  vast  importance. 

On  September  22  the  party  reached  Fort  Steele,  and,  having  completed 
the  work  of  the  season,  disbanded.  Its  members  returned  to  Washing- 
ton, there  to  prepare  the  maps  and  reports  of  the  summer's  work  during 
the  coming  winter.  Over  10,000  square  miles  were  surveyed  topograph- 
ically and  geologically  during  the  time  occupied  in  the  field.  Notes 
were  obtained  upon  the  geology,  for  the  preparation  of  a  geological 
map,  and  upon  the  agricultural  and  mineral  resources  of  the  district 
explored.  A  collection  of  Coleoptera  and  Diptera  was  made  as  com- 
plete as  time  would  permit. 

The  district  assigned  to  the  Teton  division,  directed  by  Mr.  G.  E. 
Bechler,  was  situated  between  the  parallels  43°  and  44°  15'  of  north 
latitude  and  the  meridians  109°  and  112°  of  west  longitude.  This  area 
is  drained  by  the  branches  of  Shoshone  or  Snake  River.  The  first  por- 
tion surveyed  by  this  division  lies  along  the  Blackfoot  River  and  its 
tributaries.  There  are  also  some  branches  of  Snake  River,  as  Salt, 
McCoy,  John  Gray's,  Fall,  Antelope,  Big  Sandy,  and  Willow  Creeks. 
Along  the  north  side,  and  parallel  to  the  Blackfoot  River,  is  the  Black- 
foot  range  of  mountains,  with  its  higher  portions  toward  the  west,  front- 
ing the  great  plain  of  Snake  River.  In  its  southeastern  continuation, 
near  Gray's  Lake,  this  range  is  reduced  to  a  height  of  not  more  than 
700  feet  above  the  general  level,  so  that  it  forms  a  low  plateau  divide ; 
but  south  of  Gra.y's  Lake  it  rises  until  it  attains  a  height  of  about 
8,000  feet,  about  the  sources  of  the  Salt  and  Blackfoot  Rivers. 

Along  the  southwestern  border  of  Shoshone  or  Snake  River  stretches 
another  mountain  ridge,  reaching  its  highest  point  to  the  eastward,  near 
Salt  River,  but  diminishing  in  height  as  it  follows  along  the  lower  canon 
of  Snake  River,  until  it  assumes  more  the  character  of  a  plateau,  and 
finally  terminates,  near  the  Crater  Butte  bend,  in  a  flat,  terraced  country. 

Within  this  district  Mr.  Bechler  made  thirty  topographical  stations, 
over  an  area  of  about  10,000  square  miles.  There  is  in  this  district 


764     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

a  considerable  amount  of  timber,  mostly  pine  and  poplar,  (quaking 
aspen,)  with  a  fair  average  of  arable  and  grass  land.     The  streams  con 
tain  running  water,  even  in  the  driest  portions  of  the  year. 
is  especially  adapted  to  stock-ranches,  and  must  soon  be  occupied  by 
herds  ot  cattle. 

After  having  completed  the  area  described  above,  Mr.  Bechler  re- 
turned to  Fort  Hall  for  supplies,  and  then  passed  ut)  Henry's  Fork  to 
the  northern  portion  of  the  Teton  Mountains,  where  he  spent  several 
weeks  investigating  this  snow-covered  range;  then,  crossing  Pierre's 
P.asin,  surveyed  the  lofty  group  to  which  in  1872  he  gave  the  name  of 
Pierre's  Hole  Mountains.  These  ranges  are  characterized  by  as  great 
and  inaccessibility  as  any  other  mountains  in  the  North- 


\vest. 

During  the  past  season  the  waters  of  Snake  Kiver  and  its  tributaries 
were  extraordinarily  hiyh,  owing  to  an  unusual  amount  of  snow  in  the 
mountains,  so  that  the  party  experienced  much  difficulty  and  loss  of 
time  in  crossing  the  various  streams.  The  fording  of  Snake  Kiver  has 
always  been  difficult  at  all  seasons  of  the  year.  The  Snake  and  Gros- 
ventre Rivers  flow  through  a  broad  and  beautiful  basin  or  valley,  which 
separates  the  Teton  from  the  Grosventre  Range.  The  trend  of  the  latter 
is  southeast,  and  northwest,  nearly  at  right  angles  with  the  Teton  group. 
The  Grosventre  Range,  with  the  other  parallel  ranges  to  the  south,  of 
which  Salt  RiverRange  is  one,  forms  the  dividing  barrier  between  the 
waters  ot  the  Columbia  and  Green  Rivers. 

Fronting  the  Grosventre  Range  on  the  north  rises  another  mountain 
cluster,  separated  from  the  former  by  the  Grosventre  River.  This  range 
forms  the  divide  between  the  latter  river  and  the  Buffalo  Fork  of  the 
Snake.  It  connects  with  the  main  Rocky  Mountains  near  the  sources 
of  Wind  and  Grosventre  Rivers  and  the  Buffalo  Fork  of  the  Snake, 
and  culminates  near  its  western  end  in  Mount  Leidy.  Mr.  Bechler  occu- 
pied two  weeks  in  a  careful  survey  of  a  part  of  the  Grosventre  Range, 
the  entire  Mount  Leidy  group,  with  the  Upper  Snake  River  Valley  and 
its  numerous  interesting  features. 

o^orth  of  the  Buffalo  Fork  of  the  Snake,  his  observations  extended 
into  that  densely  wooded  mountain  region  which  connects  to  the  north 
with  the  Mount  Sheridan  group,  near  the  Yellowstone,  Lewis,  and  Sho- 
shone  Lakes. 

About  the  1st  of  September  he  left  the  waters  of  Snake  River,  and 
marched  along  the  rugged  and  densely  timbered  mountain  spurs  toward 
the  Upper  Wind  River  Pass,  and,  after  crossing  the  latter,  entered 
Wind  River  Valley,  having  the  Owl  Mountains  on  the  left  and  the 
Wind  River  Range  on  the  right.  As  he  was  about  to  cross  over  the 
Warm  Spring  Pass  of  the  Wind  River  Mountains  into  the  Green  River 
Valley,  to  survey  the  southern  ends  of  the  Grosventre  and  Salt  River 
Ranges,  he  received  a  notice,  through  Indian  scouts,  from  the  com- 
mander of  the  military  post  at  Camp  Brown,  to  leave  the  country,  on 
account  of  the  danger  of  hostile  Indians.  On  this  account  nearly  a 
mouth  of  valuable  time  was  lost,  abridging  somewhat  the  results  of  the 
M-ason's  work.  Notwithstanding  the  various  difficulties  which  this 
party  encountered,  they  surveyed  an  area  of  about  6,000  square  miles  of 
t  lie  most  rugged  mountain  country  in  the  Northwest,  and  made  one  hun- 
dred and  ten  reliable  observations  with  the  mercurial  barometer.  Mr. 
Bechler,  throughout  his  district,  personally  observed  7,340  horizontal 
angles  and  f>,700  angles  of  elevation  and  depression;  and  as  they  re- 
ported backward  and  forward,  and  were  checked  by  good  barometric 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       765 

* 

readings,  they  must  give  satisfactory  results  as  to  the  altitude  of  that 
extremely  mountainous  country. 

The  following  is  a  summary  of  the  results  of  the  geological  investi- 
gations of  Mr.  Orestes  St.  John,  geologist  of  the  Teton  division: 

Commencing  with  the  area  assigned  to  the  Teton  division  of  the  sur- 
vey at  its  southwestern  corner,  the  first  five  weeks  were  devoted  to  the 
examination  of  the  region  lying  in  the  great  northern  bend  of  the  Snake 
River,  and  which  includes  an  area  of  1,700  to  2,000  square  miles. 

This  section  consists,  topographically,  of  a  series  of  more  or  less  paral- 
lel low  mountain  ranges,  of  which  the  three  principal  ones  are,  the  Mount 
Putnam  Range,  on  the  southwest,  and  which  extends  southward  into  the 
adjacent  district:  the  Blackfoot  Mountains,  in  the  central  portion;  and 
the  Caribou  Range,  which  embraces  a  rather  wide  belt  of  broken  hill 
country  and  low  mountains  along  the  eastern  border,  and  which  culmi- 
nates in  Mount  Baiubridge.  These  ranges  have  a  general  direction  west 
of  north  and  east  of  south,  and  are  separated  by  broad,  shallow  depres- 
sions, in  the  rnidst  of  which  occur  other  lesser  parallel  ridges.  To  the 
north  these  low  ranges  die  away  in  the  great  plains  of  the  Snake  Basin, 
which  comprise  about  one-third  the  area  of  the  section  here  referred  to. 

The  Snake  plains  are  everywhere  floored  with  basaltic  rocks,  which 
were  met  with  in  the  extreme  southwest  portion  of  the  district,  along 
Ross  Fork,  at  the  western  foot  of  Mount  Putnam.  To  the  northward, 
in  the  debouchure  of  Blackfoot  River,  these  rocks  rise  high  up  on  the 
flanks  of  the  hills  bordering  the  plains,  where  they  attain  elevations  of 
GOO  to  800  feet  or  more  above  the  level  of  the  plains,  toward  which  they 
incline  in  great  benches  orforelaud  slopes.  Similar  occurrences  of  basalt 
are  found  at  various  points  along  the  northern  border  of  the  hill  country ; 
the  northern  termini  of  the  Blackfoot  and  Caribou  Ranges  exhibiting 
similar  benches,  inclining  in  long,  gentle  slopes  to  the  general  level  of 
the  Snake  plains.  These  basalties  penetrate  all  the  principal  valley 
depressions  opening  to  the  southward,  forming  extensive  inlets  which 
occupy  ancient  valleys  of  erosion  in  the  sedimentaries.  The  Blackfoot 
Valley  and  the  valley  depressions  between  the  Blackfoot  Mountains  and 
the  Caribou  Range  are  floored  with  basaltics  in  every  way  similar  to  the 
deposits  occurring  in  the  Snake  plains,  and  which  extend  up  these  val- 
leys to  the  southern  boundary  of  the  district,  flooring  wide,  basin-like 
expanses  into  which  these  depressions  open  out  toward  their  sources. 
In  this  manner  the  Blackfoot  Mountains  are  surrounded,  as  it  were, 
rising  in  the  midst  of  a  basaltic  sea,  as  also  is  the  case  with  other  sedi- 
mentary ridges  in  this  region. 

The  vertical  extent  of  these  basaltic  flows,  which  doubtless  represent 
several  distinct  epochs  of  eruption,  it  is  impossible  to  decide  with  any 
degree  of  accuracy,  though  they  are  here  seen  to  reach  a  thickness  of 
several  hundred  feet.  The  extent  to  which  they  have  suffered  erosion 
is  enormous,  for  it  is  undoubtedly  true  that  they  once  in  many  places 
reached  high  up  on  the  flanks  of  the  insular  mountain  ridges,  but  where 
to-day  not  a  trace  remains  to  show  their  former  presence.  Yet  there 
are  a  host  of  phenomena  bearing  on  the  present  occurrence  and  extent 
of  these  deposits  which  require  thorough  examination  into  before  we 
can  present  even  a  general  statement  of  the  facts  which  may  finally  lead 
to  the  elucidation  of  the  history  of  this  member  of  the  volcanic  series 
in  this  region. 

These  basalts  extend  up  the  valley  of  the  Snake  as  far  as  the  lower 
basin,  where  they  are  succeeded  by  other  volcanics.  These  latter, 
mainly  trachytic  materials,  are  far  less  conspicuous  in  the  area  of  their 
50  I 


766  REPORT   OF   THE    SECRETARY    OF    THE    INTERIOR. 

exposed  occurrence  than  the  basalts,  and  are  usually  met  high  up  on 
tin-  sides,  and  even  crowning  some  of  the  highest  mountain  crests. 
They  are  al\va>s  observed  to  incline  at  greater  or  less  angles,  and  when 
seeii  in  the  ridges  along  the  northern  border  of  this  region,  they  dip  m 
the  dim-lion  ofthe  Snake  plains.  They  appear  to  be  more  ancient  than 
the  basalts,  their  connection  with  which  cannot  now  be  clearly  deter- 
mined. Toward  the  northern  terminus  of  the  Caribou  Range,  in  some  ot 
the  hi-hest  erests  in  that  quarter,  these  deposits  are  seen  to  be  under- 
laid 1>\  a  heavy  mass  of  water- worn  bowlders  and  pebbles,  cemented 
with  a  line  paste.  This  deposit  is  not  clearly  stratified.  And  again, 
within  the  lower  basin  of  the  Snake,  (that  marked  "  prairie-bottom  -'  m 
1872  map,)  similar  pebble  deposit  is  imbedded  with  alternations  of 
laminated  trachytics  and  compact  lava-basalt,  which  together  make  up 
a  thickness  of  several  hundred  feet,  gently  inclining  toward  the  center 
of  the  valley,  forming  a  sort  of  low  foreland  along  the  base  of  the 
mountain,  against  which  the  volcanics  abruptly  impinge.  In  the  valley 
of  the  Blackfoot,  where  the  party  met  with  isolated  areas  of  trachyte,  a 
heavy  mass  of  conglomerate  of  a  similar  appearance  occurs,  associated 
with  sand,  and  dipping  in  the  east  side  ofthe  valley  at  a  moderate 
angle  toward  the  Blackfoot  Mountains.  It  differs,  however,  from  the 
before-mentioned  bowlder-bed  in  being  made  up  of  a  greater  variety  of 
more  or  less  abraded  material,  including  pebbles  of  trachyte  and  lava- 
basalt,  indicating  its  more  recent  origin. 

lih^  olitic  and  other  volcanic  products  were  found  at  a  few  localities  in 
the  region.  In  one  instance  the  eruptive  matter  appears  as  a  dike  in 
the  crest  of  a  low,  short  ridge  (station  17)  between  the  Blackfoot  and 
Caribou  Ranges,  its  eruption  having  tilted  the  sedimentary  deposits  into 
an  anticlinal  ridge.  Again,  in  Mount  Baiubridge,  (station  28,)  very 
interesting  phenomena  w:ere  observed  in  connection  with  these  rocks. 
The  mountain  is  a  monoclinal  ridge,  made  up  of  sedimentaries,  between 
whose  strata  the  igneous  matter  is  intruded,  appearing  like  veritable 
beds  of  deposition,  seen  from  a  distance,  while  the  bulk  of  the  west 
poition  of  the  mountain  appears  to  consist  of  an  enormous  mass  of 
eruptive  matter  thrust  up  from  below.  Mount  Bain  bridge  would  seem 
to  be  another  instance  of  local  outburst  of  volcanic  material  similar  to 
those  brouj-  n't  to  light  by  the  survey  in  Western  Colorado.  In  the  course 
of  the  prosecution  of  the  examinations  in  the  volcanic  rocks  of  the 
district  as  complete  suites  were  secured  of  the  various  kinds  of  these 
rocks  as  it  wyas  practicable  to  transport,  and  which,  together  with  the 
notes,  will  afford  the  materials  for  an  interesting  chapter  on  this  subject. 

The  Mount  Putnam  Range  proper  is  a  monoclinal  ridge,  made  up 
of  ancient  quartzites  and  slaty  schists,  followed  by  Quebec  and  Carbo- 
niferous limestones,  dipping  generally  to  the  eastward.  The  angle  of  in- 
clination is  very  variable,  as  is  also  the  strike  of  the  strata.  In  the 
high  peak  on  which  station  1  was  located  the  mass  of  the  strata  is 
qnartzite,  which  in  places  stands  vertical  or  even  overturned  and  dip- 
ping westerly  at  a  steep  angle.  These  rocks,  together  with  the  schistose 
beds,  constitute  the  exposed  ledges  occurring  in  the  western  side  of  this 
mountain,  while  to  the  east,  doubtless,  the  Silurian  and  Carboniferous 
beds  successively  appear  in  the  lower  declivities.  But  in  the  low  ridge 
which  forms  the  northern  extension  of  the  Putnam  Range  proper  these 
ancient  quartzites  gradually  pass  out  into  the  plains,  where  they  are 
eroded  and  concealed  beneath  detrital  accumulations  and  late  volcanic 
Tertiary,  (the  latter  described  by  Bradley;)  while  the  ridge  itself,  as  its 
trend  curves  more  and  more  round  into  the  northeast,  is  crested,  first, 
by  the  Quebec  lim intone,  and  then  by  Carboniferous  limestones,  fol- 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       767 

lowed  by  obscure  exhibitions  of  the  Trias  sic,  and  finally  the  Jurassic 
deposits.  All  these  deposits  in  this  quarter  succeed  each  other  with 
apparent  regularity,  with  dips  generally  varying"  from  25°  to  45°,  but 
the  strike  gradually  passes  more  and  more  to  the  west  of  north  as  we 
pass  along  this  ridge  in  that  direction,  and  which,  together  with  evi- 
dences of  extraordinary  local  disturbance,  is  still  more  manifest  in  the 
low  range  of  hills  next  east  and  lying  between  Lincoln  Valley  and 
Blackfoot  Eiver. 

This  latter  region  embraces  a  belt  of  low  hills  and  ridges  which  cul- 
minate to  the  north  in  Higham's  Peak.  Its  northern  extremity  is  covered 
by  the  upraised  volcanic,  through  which  the  Blackfoot  has  cut  a  deep 
canon,  in  which  these  latter  deposits  are  finely  displayed.  As  it  will 
have  inferred  from  the  foregoing  brief  notice  of  the  distribution  of  the 
volcanics,  the  basalts  occur  all  along  the  eastern  flank  of  these  hills,  as 
far  south  as  the  bend  in  the  Blacklbot.  The  southern  portion  of  this 
belt  of  hills  is  connected  with  Mount  Putnam  by  a  series  of  interpolated 
ridges,  defining  the  water-shed  between  the  Portneuf  and  Ross  Fork 
drainages. 

This  belt  is  made  up  of  Carboniferous  limestones  and  siliceous  de- 
posits. Triassic  sandstones,  and  Jurassic  limestones  and  shales.  In  the 
southern  portion  of  the  belt  these  deposits  occur  in  a  rather  shallow 
synclinal,  defined  on  the  east  and  west  by  the  Carboniferous  beds.  But 
in  the  middle  and  northern  portions  these  strata  are  complicated  by  dis- 
placements and  foldings  to  such  an  extent  as  to  render  their  study  an 
exceedingly  difficult  undertaking.  Here  the  geologist  encounters  the 
most  conflicting  manifestations  of  disturbance  in  the  constant  variation 
of  dip  and  strike  exhibited  by  the  beds,  and  which,  even  in  short  dis- 
tances, change  from  moderate  inclination  in  one  direction  to  vertical  and 
inverted  position;  while  the  strike  exhibits  in  the  flexures  of  the  strata 
all  those  irregularities  which  may  be  attributable  to  violent  upheaval. 
None  of  the  later  members  of  the  Cretaceous  were  identified  in  this 
region;  but  in  the  low  border  hills  to  the  north  of  Fort  Hall  occur  ex- 
tensive deposits  of  yellowish  and  light-red  sandstone,  which  may  prove 
to  belong  to  the  earliest  epoch  of  this  period,  though  no  certain  evidence 
on  this  point  was  gained,  more  than  that  on  the  slopes  outlying  High- 
am's  Peak  on  the  west  these  beds  overlie  Jurassic  limestones. 

To  the  southeast,  in  the  region  of  the  southern  bend  of  the  Blackfoot 
River,  to  the  west,  but  somewhat  isolated  from  the  above  range  of  hills, 
in  low  isolated  hills,  and  apparently  also  making  up  the  bulk  of  low 
ridges  intervening  between  the  Blackfoot  and  a  shallow  basin  next  east 
of  Lyucoln  Valley,  an  extensive  deposit  of  light-colored  calcareous  ma- 
terial was  found,  indurated  layers  of  which  contain  great  numbers  of 
molds  of  gasteropoda,  identical  with  those  occurring  in -similar  deposits 
iu  the  region  of  the  debouchure  of  Bear  River,  and  which  have  been 
referred  to  fresh-water  forms  of  the  Pliocene.  These  beds  dip  25°  east 
ot  north,  aud  are  overlaid  by  trachyte,  also  inclining  northeast  at  an 
angle  of  15°  to  20°.  Station  30  was  located  on  one  of  these  volcanic- 
capped  Tertiary  buttes.  To  the  west  of  these  Tertiary  hills  occur  the 
conglomeratic  deposits,  dipping  from  northerly  east,  aud  finally  south- 
east 10°  to  20°,  whose  components  show  it  to  have  been  formed  subse- 
quent to  the  eruption  of  the  volcanics,  although  these  coarse  materials 
are  included  in  a  fine  paste  which  may  be  of  volcanic  origin.  In  this 
place  mention  should  not  be  omitted  of  the  existence  of  a  low  anticlinal 
axis  or  fold  in  the  volcanics  which  occupy  the  Blackfoot  Valley.  From 
all  a  hasty  trip  reveals,  it  seems  certain  that  this  region  has  been  sub- 
jected to  intense  volcanic  action  in  comparatively  recent  times. 


7G8  REPORT    OF    THE    SECRETARY    OF    THE    INTERIOR. 

The  Blackfoot  Mountains  are  mainly  composed  of  Carboniferous  strata, 
which  occur  in  a  well-defined  monoclinal  ridge,  but  which  really  forms 
the  remnant  of  an  anticlinal  fold,  the  axis  of  which  lies  about  the  mid- 
dle of  the  range,  the  strike  bending  in  and  out  but  always  crossing  the 
raii-e  obliquely;  to  the  north  the  beds  dip  off  to  the  southwest,  and  to 
the  south  inclining  northeasterly.  Blackfoot  Peak  is  a  high  culminating 
point  on  a  sort  of  spur  to  the  northeast  of  the  main  range,  beyond  which 
occur  areas  or  belts  of  variegated  early  Mesozoic  deposits.  In  the  south- 
ern portion  of  the  range,  on  the  southwest  flank,  a  considerable  thick- 
ness of  brown  arenaceous  and  limestone  deposits  comes  to  view  from 
beneath  the  Carboniferous  beds,  where  they  are  seen  to  form  the  axis 
of  the  anticlinal  fold.  These  deposits  contain  a  meager  fauna,  which 
appear  to  be  referable  to  Silurian  .forms.  The  Carboniferous  mainly 
represents  the  earlier  period,  whose  epochs  are  indicated  by  similar 
pahumtological  peculiarities  which  distinguish  the  Lower  Carboniferous 
formations  in  the  Mississippi  Basin,  and  which  more  extended  research 
will  doubtless  reveal  in  this  distant  region.  But  one  of  the  most  inter- 
esting discoveries  in  this  connection  was  the  presence  of  fish-remains, 
representing  several  forms  identical  with  or  closely  allied  to  Keokuk 
species  of  the  genera  Cladodus,  Petalodus,  Antkiodus,  Helodus. 

Between  the  Blackfoot  Mountains  and  the  Blackfoot  Eiver,  and  occu- 
pying the  angle  in  the  southern  bend  of  the  Blackfoot,  an  isolated  area 
of  hills  exhibits  a  series  of  strata,  including  the  Upper  Carboniferous  on 
the  north  to  the  Jurassic  on  the  south.  The  middle  portion  of  this  sec- 
tion is  much  disturbed  and  the  exposures  unsatisfactory.  The  former 
beds  incline  steeply  southward,  while  in  the  Jurassic  ledges  on  the 
south  a  marked  anticlinal  fold  is  observed,  the  strata  inclining  to  the 
north  and  south  either  side  of  the  axis.  Stations  12  and  13  were  located 
on  ridges  on  the  north  side  of  this  fold.  The  beds  in  this  group  of  hills 
have  veered  round  so  as  to  have  nearly  east  and  west  strike. 

To  the  southeast  of  the  Blackfoot  Mountains,  from  which  they  are 
separated  by  a  wide  basin-plain  floored  with  basalt,  rise  a  couple  of  low 
parallel  ridges,  lying  between  John  Gray's  Lake  and  the  upper  basin 
of  the  Blackfoot  River.  The  northeastern  flank  of  the  eastern  ridge 
shows  red  sandstones,  probably  Triassic  beds,  and  similar  deposits  oc- 
cur on  the  opposite  flank  of  the  western  ridge.  Their  present  condition 
is  that  of  mouoclinal  ridges,  the  strata  of  which  show  northeasterly  and 
southwesterly  dips,  respectively.  The  eastern  ridge  shows  the  basalt 
reclining  high  up  on  its  southwest  flank,  resting  on  the  Carboniferous 
limestone  near  the  crest  of  a  sag  in  the  ridge.  Both  ridges  are,  how- 
ever, principally  composed  of  Carboniferous  limestone  and  siliceous  beds. 

East  of  the  Blackfoot  Mountains,  the  first  low  mountain  eminence 
encountered  appears  to  be  a  bulging  up  of  the  volcanics,  the  basalts 
rising  up  on  the  flanks  of  the  ridge,  whose  summit  is  composed  of  sco- 
riaceous  lava.  To  the  southeast  the  basalt  has  been  denuded,  leaving 
several  low  buttes  of  this  rock,  which  seems  to  be  connected  with  the 
deposit  which  fills  the  broad  valley  separating  this  from  the  Blackfoot 
Mountains.  (Station  4.)'  But  to  the  northward,  beneath  the  basalt,  the 
nucleus  of  the  ridge  displays  a  series  of  soft  gray  sandstones  and  harder 
red,  coarse  sandstones,  with  variegated  shales,  underlaid  by  drab-gray 
limestone  containing  great  numbers  of  a  small  gasteropod,  and  which  is 
in  turn  underlaid  by  hard  light-red  sandstones.  These  beds  incline 
southwesterly,  and  together  they  represent  a  great  thickness  of  strata. 
The  ridge  on  the  north  is  capped  by  trachyte,  which  dips  at  a  steep  angle 
into  the  Snake  plains.  The  upper  sandstones  contain  obscure  vegeta- 
ble remains,  from  which  circumstance  their  Cretaceous  age  may  be  in 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       769 

ferred.  The  limestones  and  sandstones  are  again  exposed  to  view  in  a 
low  anticlinal  ridge  next  east,  which  was  thrust  up  by  a  rhyolitic  (?) 
dike,  on  which  station  17  was  established.  The  limestone  is  also  here 
charged  with  the  same  little  gasteropod,  and  underlies  the  sandstone, 
which  latter  shows  obscure  plant-remains.  The  dips  at  the  latter  local- 
ity are  southwest  and  northeast. 

To  the  southeast  of  the  above  locality,  in  the  vicinity  of  Gray's  Lake, 
obscure  outcrops  of  reddish  and  gray  sandstone  may  be  seen  in  a  cluster 
of  low  hills  just  to  the  south  of  the  lake.  These  beds  dip  at  moderate 
angles  to  the  south  west  ward,  and  on  the  westernmost  low  ridge  among 
the  debris  an  obscure  Ammonites  was  found  preserved  in  a  fragment  of 
grajT  limestone.  It  is  uncertain  whether  these  beds  should  be  referred 
to  the  Cretaceous  or  Jurassic;  but  the  fossils  obtained  will  doubtless 
readily  establish  their  age.  To  the  west  these  beds  are  doubtless  sud- 
denly and  sharply  folded,  as  the  Carboniferous  appear  in  the  before- 
mentioned  pair  of  ridges  just  west  of  Gray's  Lake  and  but  a  few  miles 
from  the  above-mentioned  exposures  with  Ammonites. 

The  Caribou  Eange  occupies  by  far  the  largest  area  of  any  range  in  this 
region,  and  in  its  geological  aspects  it  is  also  the  most  varied.  Along 
the  northeastern  border  at  intervals,  or  near  the  northern  extremity 
and  again  between  the  lower  and  upper  basins  in  the  Snake  Valley,  the 
range  is  flanked  by  heavy  deposits  of  quartzites  which  resemble  the  an- 
cient quartzites  in  Mount  Putnam.  Ihis  is  succeeded  by  the  Carbonif- 
erous, consisting  of  limestones  and  hard  quartzitic  sandstones,  in  the 
upper  portion  of  which  occurs  a  horizon  charged  with  a  peculiar  lamelli- 
branch  fauna,  which  strongly  recalls  the  Permian.  This  latter  probably 
represents  the  equivalent  of  the  Perrno  Carboniferous  in  this  region. 
Next  in  order  of  superposition  is  a  thickness  of  several  hundred  feet  of 
u  red- beds,"  which  is  in  turn  overlaid  by  the  peculiar  light  drab,  indu- 
rated, calcareous  shales  and  limestones  of  the  Jurassic.  Along  the 
western  border  of  the  range,  to  the  north,  occurs  a  heavy  series  of  red- 
dish and  soft,  gray  sandstone,  imbedded  witli  variegated  shales,  which 
contain  vestiges  of  a  flora  represented  by  obscure  impressions  of  woody 
stems  "and  dicotyledonous  leaves,  (between  stations  19  and  20.)  Higher 
in  the  mountain  slope  these  deposits  are  overlaid  by  gray  and  drab 
limestones,  which  afford  a  few  small  ostreas  and  the  pentagonal  disks  of 
crinoid  columns.  The  former  deposits  can  hardly  be  referred  to  a  more 
ancient  period  than  the  Cretaceous,  while  the  latter  as  probably  belong 
to  the  Jurassic  ;  the  relative  position  of  the  beds  indicating  a  fold  which 
overturned  or  inverted  the  strata.  These  or  very  similar  gray  sand- 
stones were  met  on  the  eastern  flank  of  Mount  Bainbridge,  where  they 
are  followed  above  by  dark  shales,  here  much  changed  by  contact  with 
the  intruded  volcanics  and  the  limestone  cap  of  the  mountain,  which 
latter  afforded  traces  of  a  little  gasteropod,  apparently  similar  to  those 
occurring  in  before  mentioned  limestones  found  elsewhere  in  connection 
with  these  gray  and  reddish  sandstones.  The  general  strike  of  these 
strata  is  northwesterly  and  southeasterly,  though  subject  to  great  varia- 
tion even  along  the  same  line  of  exposure  in  crossing  the  series ;  while 
they  are  much  folded,  which  greatly  complicates  their  study,  rendering 
accurate  measurements  impracticable  in  the  hurried  examinations  made. 
There  are  three  or  four  conspicuous  folds,  one  of  which  is  a  sort  of 
double  fold,  which  at  one  point  shows  an  abrupt  flexure  in  the  strata 
involved  which  may  at  other  points  have  completely  severed  the  bed, 
resulting  in  a  fault.  As  already  intimated,  the  region  is  further  compli- 
cated by  inverted  beds,  and  in  certain  parts  there  are  found  the  most 
contradictory  dips,  indicating  a  chaotic  condition,  the  result  of  intense 


770  REPORT    OF    THE    SECRETARY    OF    THE    INTERIOR. 

local  disturbance.  Tlio  vertical  displacement  is  very  great,  and  the 
amount  of  material  which  has  been  removed  by  erosion,  and  this,  too, 
within  a  comparatively  not  remote  date,  is  almost  inconceivably  great. 

Allusion  has  already  been  made  to  the  Mount  Bainbndge  volcanies, 
when-  these  igneous  products  are  so  intruded  in  the  limestones  and 
shales  as  to  present  the  appearance  of  regularly-bedded  deposits.  As- 
sociated with  the  eruptive  rocks  at  this  locality  are  auriferous  lodes  ot 
some  richness,  which  have  given  a  fair  supply  of  gold  to  the  placers, 
thou-h  as  yet  little  has  been  done  toward  developing  the  lodes  them,- 
Strive*.  H  'is  presumable  that  all  the  placer  diggings  in  the  Caribou 
district  received  their  gold  irom  the  lodes  intersecting  Mount  Bain- 
bridge.  The  intrusion  of  this  great  ma^s  of  eruptive  rock  does  not  ap- 
pear to  have  greatly  disturbed  the  sedimentaries,  since  the  southwest- 
erly inclinations  observed  in  ascending  the  eastern  slope  of  the  mount- 
ain are  continued  down  the  opposite  slope  and  as  far  as  Gray's  Lake 
Basin,  the  only  change  of  note  being  the  gradual  flattening  of  the  angle 
of  inclination 'as  we  recede  from  the  range  westerly.  While  the  Car- 
boniferous deposits  appear  to  be  mainly,  if  not  wholly,  restricted  to  the 
northeastern  border  of  the  range,  the  Jura-Trias  composes  the  bulk  of 
the  central  portion,  with  belts  of  the  variegated  shales  and  sandstones  of 
later  date  in  the  southwest;  all  of  which  share  equally  in  the  effects  of 
upheaval,  which  has  folded  and  warped  these  deposits  in  a  remarkable 
manner. 

There  remains  to  be  noticed  the  occurrence,  in  the  upper  basin  of  the 
Snake  Valley,  extending  up  to  the  debouchure  of  the  grand  canon,  of  a 
peculiar  deposit  of  variegated  clays  and  partially  indurated  sands,  which 
fill  this  part  of  the  valley.  These  beds  are  extensively  exposed  in  the 
right  bank  of  the  Snake  River  below  the  confluence  of  Salt  liiver,  and 
also  may  be  seen  in  the  opposite  side,  that  along  which  the  party 
traveled,  and  where  their  tilted  edges  are  planed  off  to  various  terrace- 
levels,  marking  the  work  of  the  river  erosion,  and  the  whole  overlaid  by 
the  coarse  materials  out  of  which  the  more  modern  terraces  were  formed. 
These  beds  incline  quite  uniformly  obliquely  up  stream,  or  in  an  east- 
erly direction,  at  angles  of  35°  to  40°.  Their  tilting  it  is  difficult  to  ac- 
count for,  since  they  areunconformable  to  the  older  formations  in  either 
the  east  or  west  side  ranges  bordering  the  Snake  Valley;  and  yet  it 
seems  almost  certain  that  they  owe  their  present  position  to  disturbances 
lying  to  the  westward,  in  which  case  it  may  enable  the  determination 
with  a  good  degree  of  accuracy  the  precise  age  of  at  least  (if  there  be 
more  than  one  such)  the  latest  upheavals  which  have  taken  place  in  the 
Caribou  Range.  I  take  it  these  valley  deposits  are  of  late  origin,  proba- 
bly Tertiary  lacustrine  beds. 

Below  the  month  of  Salt  River  occur  extensive  deposits  of  calcareous 
tufa,  jutting  out  into  the  valley  in  low  platforms,  in  the  neighborhood 
of  which  saline  springs  are  flowing  feebly  to-day.  Again,  in  the  little 
basin-valley  east  of  Lyncoln  Valley,  quite,  extensive  calcareous  deposits 
floor  the  valley,  in  the  midst  of  which  are  vestiges  of  the  now  extinct 
springs  from  whose  flow  this  material  was  precipitated.  The  little 
i ms  which  rise  in  the  Blackfoot  Mountains  also  contain  much  lime, 
which  isdeposiied  on  stones  and  sticks  in  the  beaver-darns  in  their  lower 
courses.  But  none  of  these  accumulations  are  comparable  to  the  enor- 
mous spring-deposits  met  with  in  the  northeastern  foot  of  the  Wind 
River  Mountains,  in  the  upper  portion  of  the  Wind  River  Valley  which 
wen-  hastily  examined  later  in  the  season. 

Reference  has  been  made  in  the  foregoing  pages  to  the  evidence  bear- 
ing on  the  age  of  some  of  the  disturbances  which  have  taken  place  iu 


GEOLOGICAL    SURVEY    OF    THE    TERRITORIES.  771 

the  Caribou  Range,  and  which  would  appear  to  have  taken  place  at  a 
comparatively  modern  date,  or  subsequent  to  the  deposition  of  the 
Tertiary  lake-beds.  In  the  valley  of  the  Blackfoot  are  found  a  set  of 
loose  sand  and  conglomerate  deposits,  which  are  apparently  of  later 
date  than  the  period  of  basaltic  effusions,  and  which  were  tilted  by  forces 
lying  to  the  westward,  the  beds  dipping  toward  the  Blackfoot  Range. 
Hence,  it  is  reasonable  to  infer  that  these  deposits,  together  with  the 
Pliocene  shell-beds  in  the  same  quarter,  were  tilted  at  the  time  of  the 
disturbances  winch  folded  and  complicated  the  strata  in  the  belt  of  hills 
lying  between  the  Blackfoot  and  Lyncoln  Valley,  and  which  does  not 
appear  to  have  affected  the  Blackfoot  Mountains,  whose  elevation  is 
probably  referable  to  an  earlier  date,  or  late  Mesozoic  time. 

In  conclusion,  it  may  not  be  out  of  place  to  mention  the  beautiful 
scenery  of  this  region,  its  grassy  hills  and  plains,  and  its  many  tracts  of 
arable  land  adjacent  to  the  numerous  little  streams  of  pure  water  which 
drain  the  region.  For  the  purposes  of  stock-growing  the  country  offers 
many  inducements.  Save  in  the  plains  bordering  the  Snake  River, 
where  excellent  crops  of  small  grain  and  vegetables  are  grown,  we  have 
not  the  aid  of  experiment  to  guide  to  positive  information  respecting 
the  agricultural  capability  of  the  tracts  of  fertile  valley-soil  everywhere 
found,  and  which  can  be  easily  irrigated.  But  even  in  the  high  basin, 
or  mountain  valley,  in  the  Caribou  district,  oats  and  the  hardier  vege- 
tables are  grown.  There  is  a  scarcity  of  wood,  and  the  largest  forest 
tracts  are  generally  in  the  most  inaccessible  localities. 

That  portion  of  the  district  next  visited  comprises  ground  which  was 
partially  explored  by  the  expedition  of  1872.  Hence,  during  the  limited 
time  the  present  party  spent  in  this  region,  it  was  principally  the  geolo- 
gist's aim  to  visit  those  quarters  which  had  not  previously  been  examined. 
This  region  embraces  all  that  portion  of  the  district  lying  in  the  great 
southern  bend  of  the  Snake  River,  extending  northward  to  the  northern 
boundary,  and  in  area  more  than  a  third  greater  than  the  previously 
noticed  region  lying  to  the  southwest.  The  whole  northern  portion  is 
occupied  by  the  plains  of  the  Snake  Basin,  which  in  the  west  and  north- 
west are  interrupted  by  a  cluster  of  low  volcanic  cones,  surrounded  by 
sand-hills.  On  the  east  the  plains  rise  into  the  broad  ridge  which  slopes 
off  from  the  northern  end  of  the  Teton  Range,  and  which  merges  into 
the  low,  densely-wooded  water-shed  separating  the  Henry's  Fork  drain- 
age on  the  west  from  the  upper  waters  of  the  main  Snake  River  on  the 
east.  The  entire  extent  of  the  plains  region,  including  the  before- 
mentioned  low  water-shed,  is  immediately  underlaid  by  volcanic  rocks. 
A  vast  sheet  of  lava-basalt  is  spread  over  the  extensive  lower  levels  of 
the  plain.  In  the  sloping  upland  border  region  to  the  south,  these 
basaltic  rocks  are  succeeded  by  a  laminated  variety,  associated  with 
trachytic  material,  which  gently  rise  upon  the  flanks  of  the  highlands 
to  the  southward,  precisely  in  the  manner  observed  in  connection  with 
the  volcanics  in  the  southwestern  portion  of  the  district.  Pierre's 
Basin,  which  lies-  between  the  Teton  Range  and  the  northern  portion  of 
the  Snake  River  or  Pierre  Mountains,  forms  a  sort  of  estuary,  opening 
out  north  into  the  Snake  plains,  up  which  the  laminated  and  trachy- 
tic volcanics  extend — on  the  east  side  as  far  as  the  mouth  of  Teton 
Pass,  and  on  the  west  side  about  half  the  distance  toward  the  head  of 
the  basin.  Formerly,  doubtless,  the  entire  area  of  this  basin  was 
floored  with  these  rocks;  but  to  day  they  are  only  observed  in  isolated 
patches,  reclining  on  the  foot  of  the  surrounding  mountains,  while  in 
the  valley  they  are  covered  by  Post  Tertiary  deposits  of  water-worn 
gravel  and  bowlders  and  the  silted  washings  from  the  surrounding 


772     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

slopes.  To  the  north  of  West  Teton  Creek,  however,  the  volcanics  con- 
stitute a  prominent  feature  in  both  the  basin  plain  and  in  the  foot  of  the 
mountains.  They  are  here  seen  to  rise  up  on  the  flank  of  the  range  to 
an  elevation  of  2,000  t>eefc  above  the  basin,  forming  a  wide,  heavily- 
timbered  foreland,  lying  between  the  mountains  and  the  plain.  lu  this 
border  region  the  streams  are  deeply  cauoned. 

In  Pierre's  Basin,  as  also  in  the  bottoms  along  Henry's  Fork  and  its 
tributaries,  accumulations  of  water  worn  drift  materials  are  prevalent, 
mainly  consisting  of  quartzite  bowlders,  with  more  rarely  limestone, 
granitic,  and  volcanic  bowlders;  the  three  former  varieties  derived  from 
ledges  in  the  Teton  Range  and  the  mountains  to  the  south  and  west. 
These  drift  materials  were  also  occasionally  observed  in  the  uplands, 
where  they  are  weathered  out  in  the  slopes  immediately  bordering  the 
canoned  courses  of  the  streams;  showing  their  general  distribution  over 
the  entire  area  of  the  volcauics.  as  well  upon  the  sloping  upland  as  in 
the  river-bottoms.  Indeed,  on  some  of  the  high  crests  in  the  northern 
part  of  the  Teton  Range,  quartzite  and  gueissose  bowlders  are  sparsely 
present  in  situations  where  their  presence  cannot  be  accounted  for  satis- 
factorily without  the  intervention  of  glacial  transporting  agencies. 

A  march  of  eight  days'  duration  from  Fort  Hall  brought  the  party  to  the 
Teton  Mountains,  near  the  northern  end  of  which,  on  the  west  side,  the 
first  ascent  was  made.  This  range,  in  its  present  condition,  may  be 
described  as  a  gigantic  mouoclinal  ridge,  with  a  metamorphic  and 
granitic  nucleus  which  forms  a  lofty,  exceedingly  rugged,  jagged  crest, 
extending  in  a  north  and  south  direction  three-fourths  the  length  of  the 
range,  and  which  culminates  in  Mount  Hayden.  The  eastern  face  is 
suddenly  broken  down  in  precipitous  walls  and  steep  slopes,  which  de- 
scend into  Jackson's  Basin.  The  western  slope  throughout  its  extent  is 
covered  by  the  sedimentaries,  dipping  to  the  westward  at  comparatively 
moderate  angle  of  inclination.  About  midway  between  West  Teton 
Canon  and  the  northern  terminus  of  the  range,  the  continuity  of  this 
sedimentary  foreland  is  suddenly  interrupted  by  a  rugged  spur  of 
Archaean  rocks,  thrown  oft'  from  the  main  range  to  the  east,  and  which 
separates  the  sedimentary  area  into  two  portions.  The  northwest  ter- 
minus of  this  spur  reaches  quite  across  the  belt  of  lofty  summits  outly- 
ing on  the  west  the  Archa3au  belt,  the  volcanic  ledges  lapping  up  on 
its  loot,  and  beneath  which  the  sedimentaries  are  concealed.  The  struc- 
tural features  of  the  range,  so  far  as  relates  to  the  sedimeutaries,  are 
comparatively  simple.  To  the  north,  where  the  volcanics  reach  high 
up  on  the  western  flank,  in  one  of  the  canoned  sources  of  the  North 
Fork  of  Pierre's  River,  the  lowest  ledges  in  situ  consist  of  a  consider- 
able thickness  of  thin-bedded  drab  limestone,  which  I  take  to  be  Quebec. 
Above  this  occurs  a  heavy  ledge  of  buff  magnesian  limestone,  showing 
a  thickness  of  100  feet  or  more,  and  which  contains  obscure  corals  re- 
sembling Xiagan  forms:  Above  the  latter,  to  the  summit  of  the  high 
ridge  on  which  station  32  was  made,  occurs  a  thickness  of  1,500  feet  of 
( 'arboniferous  deposits.  At  this  point  these  deposits  show  a  gentle  in- 
clination northwesterly  ;  but  to  the  north,  at  the  base  of  the  same  mount- 
ain, the  northeasterly  dip  of  these  strata  indicates  a  synclinal  depres- 
sion at  this  point.  Beyond,  in  the  same  directiod,  and  near  the  terminus 
of  the  range,  the  strata  are  steeply  tilted  or  upturned,  with  sharp  west- 
erly dips,  as  though  the  result  of  the  upheaval  of  the  Archa3an  ridge  which 
ics  just  to  the  east.  From  such  observations  as  Mr.  St.  John  was  able 
to  make,  it  appears  that  the  sedimentaries  which  may  once  have  folded 
continuously  round  the  north  extremity  of  the  range,  were  extensively 
denuded  prior  to  the  eruption  of  the  volcanics,  which  overlap  alike  the 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       773 

sedimentary  outlying  deposits  and  the  Archaean  areas,  wherever  the 
latter  reach,  the  western  and  northern  borders  of  the  range.  To  the  south 
of  the  above  mentioned  ArchaBan  spur,  the  same  series  of  sedimentaries 
recur,  and  which  extend  high  up  on  the  more  elevated  portions  of  the 
range,  sloping  thence  to  the  westward  in  the  direction  of  Pierre's  Basin. 
But  to  the  south,  of  the  West  Teton  Creek  Canon,  a  series  of  deep  red 
arenaceous  shales  and  sandstones  are  superimposed  on  the  Carboniferous, 
the  capping  of  intensely  hard  siliceous  roclv  or  quartzite  forming  an 
effectual  protection  to  the  foreland,  which  here  sweeps  down  in  long, 
comparatively  regular  slopes  into  the  valley.  These  latter  deposits  here 
show  a  thickness  of  300  to  500  feet.  On  the  lower  slopes  of  the  foreland, 
apparently  overlying  these  red-beds,  obscure  traces  of  drab  limestone,  not 
unlike  Jurassic  deposits  found  elsewhere  in  the  district,  occur.  Though 
no  fossils  were  observed  in  these  beds,  it  will  at  once  occur  to  you  that 
they  are  probably  Triassic.  These  red-beds  form  a  conspicuous  feature 
in  the  magnificent  escarpments  thence  southward  nearly  to  Teton  Pass 
Creek,  where  they  have  been  denuded,  the  Carboniferous  beds  again  ap- 
pearing in  the  base  of  the  mountains.  In  passing  southward  along  the 
west  flank  of  the  range,  the  inclination  of  the  sedimeutaries  is  observed 
to  gradually  change  from  a  north  of  west  to  west  and  southwest  direc- 
tion. In  the  vicinity  of  Teton  Pass,  to  the  southwest,  are  evidences  of 
unusual  disturbance,  the  Carboniferous  beds  being  suddenly  upturned, 
forming  what  appears  to  be  a  short,  sharp  fold,  with  steep  easterly  dip 
and  more  gentle  westerly  inclination.  The  pass  itself  is  eroded  out  of 
the  "red-beds"  and  siliceous  upper  deposits  of  the  Carboniferous.  While 
obscure  exposures  of  brownish  gray  limestone  containing  a  small  ostrea- 
like  shells  and  soft  gray  sandstone  indicate  the  presence  of  the  Jurassic, 
and  probably  the  Cretaceous,  which  seem  to  occupy  a  synclinal  depres- 
sion whose  axis  deviates  ncore  to  the  east  of  south  from  the  prevalent 
strike  of  the  sedimentaries  in  the  Teton  Range,  and  in  this  respect  cor- 
responding intimately  with  the  folds  afterward  observed  in  the  mount- 
ains on  the  west  side  of  Pierre's  Basin. 

The  Tetou  Range  terminates  rather  suddenly  in  lofty  peaks  sculptured 
out  of  the  sedimentaries,  to  the  south  and  southwest  of  which  a  much 
lower  but  very  broken  mountain  tract  extends  to  the  grand  caiion  of  the 
Snake  River.  This  tract  is  crossed  by  broad  belts  of  "  Red  Beds,"  drab 
and  buff  beds,  corresponding  to  the  Triassic,  Jurassic,  and,  possibly, 
Cretaceous,  and  which  are  limited  in  the  distance  by  rugged  crests  com- 
posed of  gray  ledges,  which  may  prove  to  be  the  Carboniferous  basin 
bounding  the  Snake  River.  The  high  peaks  which  rise  immediately  to 
the  north  of  Teton  Pass  summit  are  made  up  of  Carboniferous  strata, 
dipping  a  little  north  of  west  at  angles  of  10°  to  45° ;  to  the  west,  how- 
ever, the  same  deposits  incline  at  much  steeper  angle,  as  noticeable  in  the 
acclivities  on  the  north  side  of  Teton  Pass  Creek.  These  ledges  sweep 
up  over  the  summit  of  the  range,  forming  lofty  ridges  which  break 
down  abruptly  on  the  east  in  a  succession  of  escarpments  and  steep  de- 
bris covered  slopes.  East  of  the  summit  of  Teton  Pass,  in  descending 
to  Jackson's  Basin,  the  granitic  nucleus  cannot  lie  far  beneath  the  bed 
of  the  caiion,  since  the  short  northern  tributary  canons  have  brought 
down  much  granitic  debris;  but  below  this  still,  in  a  bulky  outlying 
ridge  at  the  debouchure  of  East  Pass  Creek,  the  Carboniferous  again  ap- 
pears, also  dipping  north  of  west  at  a  moderate  angle.  Farther  north, 
in  these  east-lacing  sedimentary  escarpments,  where  the  whole  series  of 
Palleozoics  occurring  in  this  region  is  revealed  in  magnificent  exposures, 
a  fold  or  undulation  in  the  strata  is  observed  by  which  the  Carboniferous 
beds  are  carried  down  along  the  east  slope  to  a  level  far  below  the  lofty  sum  - 


774  REPORT   OF   THE    SECRETARY    OF    THE    INTERIOR. 

mits  which  the  beds  crown  along  the  crest  of  the  range  ;  a  similar  fold 
would  explain  the  occurrence  of  the  low-lying  exposures  in  th,e  debouch- 
ure of  East  Pass  Creek,  above  noticed.  Beneath  the  sedimeutaries  at 
this  point  the  Archaoan  rocks  are  exposed,  and  which  descend  in  steep, 
rugged  slopes  to  the  level  of  the  valley.  To  the  north  still,  the  Archasau 
nucleus  rises  higher  and  higher,  carrying  up  with  it  tlje  sedimentaries, 
which  gradually  disappear,  one  formation  after  another,  until  only  Que- 
bec is  seen,  forming  a  coping  ot  dark  limestone  to  some  of  the  high  ridges 
south  of  Mount  Haydeu,  and  where  they  are  finally  crowded  back,  occu- 
pying subordinate  ridges  west  of  the  main  crest.  The  east  face  of  the 
range  from  the  vicinity  of  the-Tetons  to  its  northern  extremity  shows 
onlv  the  Archraan  rocks.  It  is  very  probable  that  the  sediineutaries 
were  profoundly  faulted  along  the  east  side  of  the  range,  along  which 
side,  it  would  appear,  the  greatest  force  was  expended  in  the  upheaval. 
But  toward  the  extremities  of  the  range,  where  these  forces  were  less 
violent,  the  sedimentaries  may  have  been  merely  crumpled  or  folded  in 
the  manner  apparent  in  the  southern  extremity  of  the  range. 

Subsequent  erosion  has  greatly  changed  the  surface  contour,  and  ob- 
scured many  details,  but  the  general  features  are  still  manifest. 

A  brief  visit  to  the  Pierre  Mountains,  on  the  west  side  of  Pierre's 
Basin,  afforded  opportunity  for  the  study  of  the  structural  features  of 
the  eastern  half  of  the  range.  This  range  intersects  the  Teton  Range 
at  a  sharp  angle,  its  general  direction  being  northwest  and  southeast, 
and  forming  an  exceedingly  broken  mountainous  belt  between  Pierre's 
Basin  and  the  Snake  River.  In  its  geological  structure  it  is  inti- 
mately related  to  the  Caribou  Range  on  the  opposite,  west,  side  of  the 
Snake  River.  The  range  exhibits  a  series  of  folds,  whose  axes  extend  in 
a  general  direction  northwesterly  and  southeasterly,  and  in  which  are 
exposed  typical  exhibitions  of  the  Carboniferous,  Ti lassie,  and  Jurassic, 
and  probably  the  Cretaceous  formations.  Along  the  eastern  border,  to- 
ward the  northern  extremity  of  the  range,  in  a  section  'much  compli- 
cated and  broken  up  by  the  forces  which  folded  the  beds,  occur  a  series 
of  gray  sandstones  and  shales  which  closely  resemble  deposits  found  in 
the  Caribou  Range,  which  have  been  referred  to  the  Cretaceous.  These 
beds  appear  in  low  ridges,  upon  which  lap  the  volcanics  in  long,  gentle 
ascents  from  the  canon-scored  plain  of  Pierre's  River  to  the  northeast 
and  north.  To  the  southwest  a  wide  belt  of  Carboniferous  is  met,  show- 
ing the  entire  thickness  of  the  formation,  which  is  made  up  of  lime- 
stones and  heavy  siliceous  deposits.  On  the  southwest  side  of  the  anti- 
clinal in  which  these  limestones  are  exposed,  a  heavy  series  of  deep  red 
gritty  shales  and  sandstones,  reaching  a  thickness  of  1,500  feet  or  moie, 
occur,  which  represent  the  Triassic.  Succeeding  the  latter,  occur  a  sec 
of  beds  made  up  of  limestones  and  drab  indurated  calcareous  layers, 
with  Jurassic  fossils,  representing  a  thickness  of  a  thousand  feet  or 
more.  These  are  followed  by  a  series  of  heavy  deposits  of  hard  sand- 

_.  .1 _;.___  i  .    i        i  j  •  •• 


similar  deposits  are  here  and  there  indicated,  bounded  in  the  distance 
by  the  more  uniform  and  even  loftier  mountain  wall  along  the  northeast 
margin  of  the  Snake  Valley,  which  appears  to  consist  of  Carboniferous 
strata.  These  several  folds,  so  far  as  I  was  able  to  determine,  are  pretty 
constant  for  long  distances.  Although  the  middle  part  of  the  rano-e 
has  been  much  eroded,  so  as  to  cause  the  Carboniferous  to  flank  the 
mountains  between  Horse  Creek  and  the  head  of  Pierre's  Basin  the 
outer  belt  of  Cretaceous  near  the  northern  end  of  the  range  probably 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       775 

belongs  to  the  same  fold  which  lies  just  to  the  southwest  of  Teton  Pass  ; 
while  the  inner  folds  above  alluded  to  correspond  to  those  observed  in 
the  southeastern  half  of  the  range  to  the  southwest  of  Teton  Pass.  The 
condition  of  the  sedimentaries  in  the  interval  embraced  to-day  in  Pierre's 
Basin,  of  course  remains  conjectural,  these  rocks  being  hidden  from  ob- 
servation beneath  the  volcanic  sheet  which  at  a  later  date  flooded  the 
valley.  From  the  relative  age  of  the  folding  of  the  strata  which  make  up 
this  range,  compared  with  other  neighboring  ranges,  it  seems  probable 
that  the  date  of  its  upheaval  is  referable  to  a  time  antecedent  to  that  dur- 
ing which  the  disturbances  took  place  which  resulted  in  the  folding  of 
the  Caribou  Range,  and  probably  subsequent  to  the  upheaval  of  the  Teton 
Range.  This  latter  forms  a  unique  as  it  is  one  of  the  grandest  ranges 
in  the  West.  In  many  particulars  it  bears  a  more  striking  resemblance 
to  the  Wind  River  Mountains  than  it  does  to  the  low  but  much  more 
complicated  ranges  which* it  dominates. 

That  which  forcibly  strikes  the  observer  on  entering  Jackson's  Basin, 
which  lies  at  the  east  base  of  the  Teton  Range,  is  the  vast  accumulation 
of  drift  materials  with  which  the  valley  is  filled.  Along  the  west  side 
of  the  basin  extensive  morainic  accumulations  in  irregular,  wooded  ridgos, 
outlying  the  debouchures  of  the  canons  which  penetrate  the  range;  while 
the  stream  itself,  in  various  stages,  has  fashioned  these  materials  into 
beautiful  terrace  formations.  Scarcely  anything  could  offer  greater  con- 
trast than  that  presented  by  the  mountain  environments  of  this  basin. 
The  Teton  Range  forms  a  rugged,  almost  precipitous  barrier  on  the  west, 
which  rises  4,000  to  7,000  feet  above  the  valley.  To  the  east  the  country 
rises  in  gentle,  wooded  ascents,  culminating  in  clusters  of  low  mountain 
elevations  which  are  connected  by  high  mountain  plateaus  with  the  con- 
tinental water-shed.  To  the  southeast  of  the  Teton  range,  and  running 
up  into  the  angle  formed  by  the  confluence  of  the  Snake  and  Grosventre 
Rivers,  lies  a  rather  lofty  and  very  rugged  range  of  mountains  which 
occupies  a  considerable  area  between  the  Grosventre  and  the  headwaters 
of  Green  River,  and  which  forms  a  sort  of  transverse  belt  connecting  the 
Teton  Range  with  the  Wind«River  Mountains  to  the  east.  This  range 
is  known  as  the  Grosventre  or  Wyoming  Mountains.  ^The  geologist's 
examinations  wer/e  confined  to  the  western  portion  of  the  range.  Here 
he  meets  with  an  Archasan  (gueissic)  nucleus,  which  in  places  penetrates 
through  the  heavy  mantle  of  sedimentaries  in  sharp  peaks  which  but 
for  the  presence  of  the  colossal  Tetons  would  elicit  admiration  for  their 
real  grandeur  and  perfect  mountain  contour.  In  many  respects  the 
range  presents  marked  resemblance  to  the  Teton  Range,  and  probably 
its  relationship  to  the  Wind  River  Mountains  is  even  more  intimate. 
The  sediuieutaries  have  been  uplifted  bodily  upon  portions  of  the  range, 
though  they  exhibit  evidences  of  great  disturbance  and  of  .the  unequal 
distribution  of  the  elevatory  forces,  which  have  in  places  sharply  folded 
the  strata.  One  of  these  Archa3an  peaks  sends  down  a  sharp  spur  to  the 
westward,  which  terminates  ratherabruptly  in  the  valley  at  a  point  about 
opposite  the  Lower  Grosventre  buttes.  Between  the  latter  and  the 
foot  of  the  spur,  a  little  stream  has  excavated  a  widish  valley,  in  the 
west  side  of  which,  in  a  line  of  bluffs,  dark  weathered  ledges  appear, 
gently  dipping  westerly,  and  which  are  probably  Quebec.  In  the  north- 
ern butte,  Professor  Bradley  mentions  having  observed  volcanic  ledges 
("  porphyriiic  breccias,"  )  and  to  the  south  limestones  in  horizontal  posi- 
tion, which  are  referred  to  the  Carboniferous.  The  volcanic  capping 
gradually  rises  to  the  southeast,  and  finally  disappears.  A  similar  rem- 
nant occurs  on  Elkhorn  Creek,  near  the  edge  of  the  basin,  where  ifc  rests 
upon  Tertiary  deposits.  To  the  north  of  the  above-mentioned  spur,  in 


776     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

the  foot  of  the  foreland,  outcrop  ledges  of  thin-bedded  drab  limestone, 
dipping  northwesterly,  which  are  undistinguishable  from  the  Quebec 
limestones  occurring  in  the  Teton  Range.  Ascending  this  foreland,  east- 
ward, the  same  limestones  are  exposed  at  frequent  intervals,  showing 
the  same  dip,  and  iu  places  overlaid  by  remnants  of  the  buff  magnesian 
limestone  referred  to  the  Niagara.  These  deposits  finally  give  way  to 
densely  wooded  debris  slopes,  which  reach  up  to  the  Archaean  peak  of 
station  44,  like  gigantic  moraines.  From  this  point  an  excellent  oppor- 
tunity is  had  for  the  study  of  the  rugged  and  almost  inaccessible  mount- 
ain highlands  which  make  up  the  broad  northern  summit  of  the  Gros- 
ventre  Range.  It  is  a  region  of  lofty  ridges  and  profound  amphitheaters, 
whose  precipitous  walls  exhibit  the  complete  sedimentary  series  from 
quartzites  to  the  Carboniferous,  and  off  to  the  east  heavy  deposits  of  the 
Triussic  u  red  beds  "  cap  high  ridges.  The  region  strongly  recalls  the 
Teton  Range,  but  the  sedimentaiies  are  much*  more  disturbed,  and,  as  a 
consequence,  this  highland  is  more  uneven  than  that  along  the  west 
summit  of  the  latter  range.  A  few  miles  to  the  northward,  the  foreland 
which  rises  into  station  46  from  the  debouchure  of  the  Grosventre,  ex- 
hibits the  Carboniferous  dipping  northerly,  and  which  extends  to  the 
summit  of  this  lofty  peak.  These  beds  pass  beneath  the  Triassic,  which 
appears  in  line  of  vermillion  bluffs  along  the  north  side  of  Grosventre 
Canon,  beyond  which  the  hills  gradually  rise  into  a  high  conical  peak 
which  forms  the  culminating  point  of  the  highlands  between  the  Gros- 
ventre and  Buffalo  Fork,  and  which  is  known  as  Mount  Leidy.  Over- 
lying the  Triassic  red  beds,  a  broad  belt  shows  light  drab  deposits 
which  also  dip  norther-ly,  and  which  hold  the  position  and  have  the  ap- 
pearance of  the  Jurassic,  though  no  fossils  were  observed  in  the  lime- 
stones, which  in  part  make  up  these  latter  deposits,  by  which  their  age 
could  be  determined.  The  space  intervening  between  the  latter  depos- 
its and  Mount  Leid>  is  more  broken,  and  apparently  consists  of  an  ex- 
tensive accumulation  of  softer  deposits.  The  lower  portion  of  these  are 
found  to  consist  of  light  and  yellowish  soft  sandstones  and  clays,  capped 
by  light-brownish  beds,  which  are  finely  displayed  in  Mount  Leidy, 
whose  steep  slopes  the  elements  have  beautifully  sculptured.  Iu  the 
northern  foot  of  Mount  Leidy,  the  lower  or  middle  beds  of  this  series 
exhibit  an  exposure  of  one  or  two  hundred  feet  in  canon-bluffs  of  Elk- 
horn  Creek,  in  the  base  of  which  a  thin  bed  of  rotten  lignite  was  found. 
He  failed  to  detect  any  traces  of  organic  remains  in  these  beds,  and  am, 
in  consequence,  unable  to  refer  them  to  their  place  in  geological  time, 
though  I  believe  they  belong  to  the  Tertiary.  The  northerly  inclination 
of  these  beds  at  a  gentle  angle  continues  across  the  low  upland  to  the 
Buffalo  Fork,  and  in  the  hills  which  rise  on  the  north  of  this  stream  simi- 
lar beds  of  clays  and  buff  sandstone  outcrop,  where  they  attain  eleva- 
tion of  above  2,000  feet  above  the  valley.  Th«-se  bills 'are,  capped  by 
bed  of  partially  cemented  bowlders  and  pebbles,  the  degradation  of 
which  has  strewn  the  slopes  with  drift  debris.  The  above-mentioned 
Tertiary  deposits  were  met  in  the  gradually-ascending  upland  to  the 
east  as  high  up  as  the  debouchure  of  the  Buffalo  Fork,  though  they 
were  not  observed  to  extend  up  on  the  mountain  sides  iu  this  quarter. 
From  the  Buffalo  Fork  the  route  led  up  Black  Rock  Creek,  through 
the  To-owo-tu  Pass,  across  the  continental  divide  into  the  Wind  River 
Valley.  Just  wiihin  the  western  entrance  to  the  pass,  on  the  north 
side,  ii  group  of  high  mountains  occupies  the  interval  between  Black 
Rock  Creek  and  Buffalo  Fork,  of  which  Buffalo  Fork  Peak  forms  the 
culmination.  The  bases  of  these  mountains,  together  with  the  corre- 
sponding heights  on  the  opposite  side  of  Buffalo  Fork,  and  which  together 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       777 

form  the  gateway  to  the  upper  mountain  valley  of  this  stream,  are  com- 
posed of  Archaean  (gneissose)  rocks,  which  constitute  a  thousand  or  more 
feet  of  the  lower  portion  of  fche  canon-walls.  Upon  these  rests  a  thickness 
of  one  hundred  feet  or  more  of  quartzite,  and  upon  the  latter  a  heavy  ledge 
Of  the  lower  Quebec  limestone  occurs,  forming  the  summit  of  Buffalo  Fork 
Peak.  This  mountain  is  connected  with  the  lower  peak,  station  40,  to 
the  southwest,  by  a  long  spur,  in  which  this  limestone  forms  the  coping 
and  dips  in  the  same  direction.  It  is  overlaid  by  the  thin-bedded  upper 
ledge,  with  a  considerable  thickness  of  intervening  clays  and  indurated 
fine-grit  layers,  in  all  of  which  Trilobites  and  other  Silurian  fossils  were 
found.  These  beds  are  in  turn  overlaid,  without  apparent  unconfor- 
mability,  by  several  hundred  feet  of  Carboniferous,  which  latter  crowns 
the  summit  of  station  49.  The  southern  slopes  of  these  mountains 
steeply  descend  over  heavy  ledges  of  limestone  and  grayish  buff  and 
reddish  hard  sandstone  into  the  valley  of  Black  Rock  Creek,  where  the 
deep  red  sandy  shales  and  sandstone  of  the  Triassic  outcrop,  and  the 
presence  of  which  in  the  adjacent  slopes  is  plainly  hinted  by  the  rank  her- 
baceous vegetation  its  soil  supports.  The  same  deposits  are  also  seen  to 
the  east  or  southeast,  reclining  on  the  southeasterly  declivities  of  these 
mountains,  in  the  gap  which  separates  them  from  the  volcanic  escarp- 
ments of  the  main  water-shed.  This  group  of  mountains  appears  to  owe 
its  origin  to  a  local  bulging  of  the  crest,  since  to  the  north  th<*  sedimen- 
taries  which  it  bears  on  its  crest  are  seen  to  dip  off  in  that  direction,  as 
they  do  in  the  opposite  direction  on  their  western  and  southern  flanks, 
overlooking  the  lower  valley  of  the  Buffalo  Fork  and  the  upper  course 
of  Black  Rock  Creek  in  the  approach  to  To-owo-tu  Pass.  The  latter 
valley,  like  the  Teton  Pass,  (and  for  that  matter,  so  many  of  the  passes 
in  the  mountains  of  this  region,)  is  excavated  in  the  Triassic  red-beds. 
To  the  southwest  of  the  Black  Rock  indications  of  the  presence  of  the 
Jurassic  are  obscurely  revealed  here  and  there,  but  soon  concealed  in 
the  long,  wooded  slopes,  which  are  continuous  with  the  Tertiary  ridges 
of  the  Mount  Leidy  region. 

In  the  valley  of  Black  Rock  Creek  are  encountered  heavy  masses  ot 
volcanics  consisting  largely  of  a  sort  of  conglomerate  breccia.  These 
continue  to  the  summit  of  To-owo-tu  Pass,  where  they  are  seen  in  inti- 
mate association  with  some  of  the  most  remarkable  volcanic  accumula- 
tions. The  latter  rise  into  lofty  horizontally-bedded  mountains  whose 
sides  are  sculptured  in  colossal  architectural  forms,  and  which  form  a 
grand  portal  to  the  pass  across  the  continental  divide.  The  heights 
command  Jackson's  Valley  and  the  Teton  to  the  westward,  while  to  the 
eastward  lies  the  low  country  of  the  Wind  River  Valley,  diversified  by 
the  peculiar  variegated  formations  which  occupy  a  great  basin  bounded 
on  the  north  by  the  continuation  of  the  volcanic  cliffs.  These  latter 
offer  on  close  examination  the  most  varied  appearance,  being  made  up 
of  volcanic  ash,  sands,  breccias,  and  conglomerate,  which  are  partly  of 
aqueous  origin,  as  shown  by  their  bedderl  coudition.  These  strata  are 
practically  horizontal,  although  they  incline  slightly  in  various  direc- 
tions, but  appear  not  to  have  been  affected  by  disturbances  such  as  ele- 
vated the  Buffalo  Fork  Mountains,  and  hence  the  more  recent  date  of 
their  formation  is  inferred. 

To  the  east,  north,  and  northwest,  these  deposits  are  spread  over  an 
immense  area  of  elevated  mountain  country,  themselves  constituting 
some  of  the  highest  elevations  in  the  region.  Their  debris  effectually 
conceals  the  older  rocks  in  the  To-owo-tu  Pass,  to  the  south  of  which 
the  same  great  escarpments  are  continued  for  a  short  distance,  when 
they  give  way  to  lower  levels  of  long,  wooded  mountain  summits.  In 


778     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

the  latter  appear  heavy  exposures  of  dark,  compact,  and  scoriaceous 
lavas,  with  trachytic  domes.  These  extend  along  the  summit  of  the 
water-shed  several  miles  in  a  southerly  direction,  and  may  reach  to  the 
near  vicinity  of  Union  Pass. 

Descending  into  the  Wind  River  Valley,  a  few  miles  below  the  summit 
of  the  pass,  the  bluff  banks  along  the  stream  show  a  hundred  feet  or  so 
of  cream-colored  and  bnff  sandstone  and  gritty  clays.  These  deposits 
gradually  increase  in  vertical  exposure  as  we  descend  the  valley,  the 
beds  gentl?  inclining  in  the  same  direction,  or  southeasterly.  At  a  point 
where  the  stream  opens  out  into  the  intervale-bordered  valley  these  beds 
are  seen  to  be  overlaid  by  a  series  of  variegated,  red,  greenish,  and  buff 
or  ash  colored  clays,  and  indurated  arenaceous  beds,  which  make  up  a 
thickness  ot  several  hundred  feet  in  a  rather  high  plateau  or  terrace 
outlying  the  high  volcanic  ridges  which  hem  the  basin  on  the  north. 
These  deposits  continue  down  the  valley  several  miles  farther,  lower 
beds  coining  to  view  as  we  descend.  Above  De  Noir  Creek,  in  a  low 
bluff  on  the  north  side  ot  Wind  River,  a  thin  seam  of  lignite  occurs  in 
connection  with  bluish-drab  and  chocolate-colored  clays  and  rusty,  soft 
sandstone.  In  the  neighborhood  of  Warm  Water  Creek  we  first  met  the 
older  sidimentaries,  which  appear  in  a  mass  of  reddish  and  light  colored 
sandstones  reclining  on  the  toot  of  the  Wind  River  Mountains,  (lipping 
20°  to  30°  northeasterly.  The  sandstones  are  underlaid  by  older  for- 
mations, which  rise  successively  higher  and  higher  upon  the  northeast- 
ern face  of  the  range. 

In  the  same  neighborhood,  on  the  northeast  side  of  the  river,  a  series 
of  beautifully  exposed  deposits,  consisting  of  variegated,  light-red,  and 
drab  clays,  and  bands  of  'ferruginous  sandstone,  capped  by  yellowish 
sandstone,  appear,  and  which  seem  to  underlie  conformably  the  before- 
mentioned  horizontal  deposits.  These  variegated  beds  continue  thence 
far  down  the  valley;  but  above  Crow  Heart  Butte  they  are  crowded  in- 
land, the  terraces  which  bound  the  stream  showing  buff'  sandstones,  and 
which,  together  with  brownish  clays,  make  up  the  rock  exposed  in  the 
above-named  butte.  In  the  vicinity  of  the  confluence  of  North  Fork 
the  variegated  beds  exhibit  their  greatest  development,  as  shown  at 
any  one  point  observed.  Here  they  are  seen  to  rest  upon  brown  clays, 
recalling  the  clays  interbedded  with  the  sandstones  in  Crow  Heart 
Butte,  and  all  of  which  rest  unconformably  upon  the  more  steeply- 
inclined  Jurassic  limestone  and  Triassic  sandstone,  which  here  form  a 
wide  belt  of  exposures  in  the  foot  of  the  mountain.  The  variegated 
beds  are  also  slightly  inclined  northeasterly. 

Below  Bull  Creek  we  soon  enter  a  region  where  the  Mesozoics  extend 
several  miles  out  into  the  plains,  which  here  intervene  between  the  river 
and  the  foot  of  the  mountains;  a  section  where  they  exhibit  much  dis- 
placement, which  contrasts  with  the  grand  simplicity  which  uniformly 
characterizes  the  position  of  the  Mesozoic  and  Paleozoic  formations  in 
the  great  foreland  slopes  of  the  range  between  the  Warm  Water  and 
Little  Wind  Rivers. 

Thence,  on  their  return,  the  party  passed  through  Mr.  Chittenden's 
district,  which  was  visited  by  Dr.  Endlich. 

The  necessity  of  a  careful  examination  of  the  various  geological  for- 
mations in  the  field,  and  a  review  by  a  practical  paleontologist  of  the 
various  districts  that  have  from  year  to  year  been  surveyed  by  the  dif- 
ferent geologists  of  this  and  other  surveys,  has  been  long  felt.  Such  a 
work,  indeed,  was  imperatively  necessary  before  a  consistent  and  com- 
prehensive classification  of  the  formations  could  be  established.  This 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       779 

duty  was  assigned  to  Dr.  0.  A.  White,  the  palaeontologist  of  this  Survey, 
and  he  took  the  field  at  the  beginning  of  the  past  season  and  continued 
his  labors  until  its  close.  The  special  duty  with  which  he  was  charged 
was  to  pursue  such  lines  of  travel  as  would  enable  him  to  make  critical 
exam  i nation  of  the  geological  formations  in  succession  as  they  are  exposed 
to  view  on  both  sides  of  the  Rocky  Mountain  chain,  and  also  on  both 
sides  of  the  Uintah  chain  ;  to  collect  and  study  the  fossils  of  these  forma- 
tions in  such  detail  as  to  settle,  as  far  as  possible,  the  questions  of  the 
natural  and  proper  vertical  limits  of  the  formations,  their  geographical 
range,  their  correlation  with  each  other,  and  to  define  the  paleontologi- 
es! 1  characteristics  of  each. 

He  has  pursued  his  researches  with  such  success  during  the  past  sea- 
son as  to  demonstrate  the  necessity  of  continuing  this  class  of  investi- 
gations by  various  lines  of  travel  across  what  is  generally  known  as  the 
great  Rocky  Mountain  region,  especially  those  portions  of  it  that  have 
been  surveyed,  as  well  as  those  in  which  surveys  are  in  progress. 

Among  other  important  results,  he  has  shown  the  identity  of  the  lig- 
nitic  series  of  strata  east  of  the  Rocky  Mountains  in  Colorado  with  the 
Fort -Union  group  of  the  Upper  Missouri  River,  and  also  its  identity 
with  the  great  Laramie  group  of  the  Green  Riwr  Basin  and  other 
portions  of  the  region  west  of  the  Rocky  Mountains.  He  also  finds 
the  planes  of  demarkation  between  any  of  the  Mesozoic  and  Cenozoic 
groups,  from  the  Dakota  to  the  Bridger  inclusive,  to  be  either  very  ob- 
scure or  indefinable;  showing  that  whatever  catastrophal  or  secular 
changes  took  place  elsewhere  during  all  that  time,  sedimentation  was 
probably  continuous  in  what  is  now  that  part  of  the  continent  from  the 
earliest  to  the  latest  of  the  epochs  just  named.  Other  results  and  further 
details  of  the  season's  work  will  appear  in  the  following  paragraphs. 

The  general  course  of  travel  pursued  by  Dr.  White  during  the  season 
was  as  follows,  not  including  the  numerous  detours,  meanderings,  and 
side  trips  which  the  work  necessitated  :  Outfittingat  Cheyenne,  he  jour- 
neyed southward,  traversing  in  various  directions  a  portion  of  the  great 
plains  which  lie  immediately  adjacent  to  the  eastern  base  of  the  Rocky 
Mountains  in  Colorado.  The  most  easterly  point  thus  reached  was  some 
sixty  miles  east  of  the  base  of  the  mountains  and  the  most  southerly 
point  about  twenty-five  miles  south  of  Denver.  Returning  to  Denver  to 
renew  his  outfit,  he  crossed  the  Rocky  Mountains  by  way  of  Boulder 
Pass,  through  Middle  Park.  After  making  certain  comparative  exam- 
inations of  the  Mesozoic  and  Ceuozoic  formations  in.  Middle  Park  he 
proceeded  westward  to  the  headwaters  of  the  Yam  pa  River,  following 
that  stream  down  to  the  western  foot-hills  of  the  Park  Range  of  mount- 
ains. 

Here  resuming  his  comparative  examinations  of  the  Mesozoic  and 
Cenozoic  strata,  he  passed  down  the  valley  of  the  Yampa  as  far  as  Yam  pa 
Mountain,  one  of  those  peculiar  and  remarkable  up-thrustsof  Paleozoic 
rocks  through  Mesozoic  strata.  In  all  this  area,  as  well  as  that  between 
the  Yampa  and  White  Rivers,  the  Laramie  group  reaches  a  very  great 
and  characteristic  development,  and  it  received  careful  investigation, 
yielding  some  of  the  most  important  results  of  the  season's  work. 
Crossing  the  ground  between  the  two  rivers  named  to  WThite  River  Indian 
agency,  thence  down  White  River  Valley  about  one  hundred  miles; 
thenc'e  to  Green  River,  crossing  it  at  the  southern  base  of  the  Uintah 
Mountains,  making  many  detours  on  the  way,  he  reviewed  the  geology 
of  the  region  which  he  had  surveyed  during  the  previous  season.  This 
review  brought  out  not  only  the  important  paleontological  facts  before 
referred  to,  but  it  also  added  materially  to  the  elucidation  of  the  geological 


780  REPORT    OF    THE    SECRETARY    OF    THE    INTERIOR. 

structure  of  the  region  which  lies.between  the  eastern  end  of  the  Uintah 
Mountain  Range  on  the  west  and  the  Park  Range  on  the  east, 

Hrvond  Green  River  he  pursued  his  travels  westward,  studying  the 
Mesozoic  and  Cenozoic  strata  that  flank  the  Uintah  Range  upon  its  south 
side,  and  making  comparisons  of  both  their  lithological  and  paleonto- 
logical  characteristics. 

In  this  \v;iy  he  traversed  the  whole  length  of  the  Uintah  Range,  cross- 
ing at  its  junction  with  the  Wasatch  Range  over  into  the  valley  of  Great 
Salt  Lake.  Recrossing  the  Wasatch  to  the  north  side  of  the  Uintah 
Range  he  continued  his  examinations  of  the  Cretaceous  and  Tertiary 
strata  into  and  entirely  across  the  great  Green  River  Basin,  leaving  the 
field  at  the  close  of  the  season  at  Rawlius  Station,  on  the  Union  Pacific 
Railroad. 

A  general  statement  of  the  results  of  the  season's  work  has  been 
given  in  a  previous  paragraph,  but  the  following  additional  summary 
will  make  the  statement  somewhat  clearer,  being  made  after  the  route 
of  the  season's  travel  has  been  indicated.  The  formations  of  later 
Mesozoic  and  earlier  Cenozoic  ages,  especially  those  to  which  Dr.White, 
in  former  publications,  has  applied  the  provisional  designation  of  "Post- 
Cretaceous,"  have  received  particular  attention.  The  extensive  explora- 
tions of  Dr.  Hayden  in  former  years,  and  the  paleoutological  investi- 
gations of  the  late  Mr.  Meek,  pointed  strongly  to  the  equivalency  of  the 
Fort  Union  beds  of  the  Upper  Missouri  River  withXhe  lignitic  formation 
as  it  exists  along  the  base  of  the  Rocky  Mountains  in  Colorado,  and 
also  to  the  equivalency  of  the  latter  with  the  Bitter  Creek  series  west 
of  the  Rocky  Mountains.  The  investigations  of  this  year  have  fully 
continued  these  views  by  the  discovery  not  merely  of  one  or  two  doubt- 
ful species  common  to  the  strata  ot  each  of  these  regions,  but  by  an 
identical  molluscan  fauna  ranging  through  the  whole  series  in  each  of 
the  regions  named. 

This  shows  that  the  strata  just  referred  to  all  belong  to  one  well- 
marked  period  of  geological  time,  to  the  strata  of  which  Mr.  King  has 
applied  the,  name  of  "  Laramie  group,"  (Point  of  Rocks  group  of 
Powell.)  His  investigations  also  show  that  the  strata,  which  in  former 
reports  by  himself  and  Professor  Powell  have  been  referred  to  the  base 
of  the  Wasatch  group,  also  belong  to  the  Laramie  group,  and  not  to 
the  Wasatch.  He  has  reached  this  later  conclusion  not  merely  because 
there  is  a  similarity  of  type  in  the  fossils  obtained  from  the  various  strata 
of  the  Laramie  group  with  those  that  were  before  in  question,  but  by 
the  specific  identity  of  many  fossils  that  range  from  the  base  of  the 
Laramie  group  up  into  and  through  the  strata  that  were  formerly  re- 
ferred to  the  base  of  the  Wasatch.  Furthermore,  some  of  these  species 
are  found  in  the  Laramie  strata  on  both  sides  of  the  Rocky  Mountains. 
Thus  the  vertical  range  of  some  of  these  species  is  no  less  than  three 
thousand  feet,  and  their  present  known  geographical  range  more  than  a 
thousand  miles. 

Besides  the  recognition  of  the  unity  of  the  widely-distributed  mem- 
bers of  the  formation  of  this  great  geological  period,  bounded  by  those 
of  undoubted  Cretaceous  age  below  and  those  of  equally  undoubted 
Tertiary  age  above,  his  further  observations  have  left  comparatively  little 
doubt  that  the  <•  Lake  Beds"  of  Dr.  Hayden,  as  seen  in  Middle  Park 
the  "  Brown's  Park  group  "  of  Professor  Powell,  and  the  "  Uintah  group" 
of  Mr.  King,  all  belong  to  one  and  the  same  epoch,  later  than  and 
distinctly  separte  from  the  Bridger  group. 

In  that  portion  of  the  region  which  lies  adjacent  to  the  southern  base 
of  the  Uintah  Mountain  Range,  and  which  is  traversed  by  Lake  Fork 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       781 

and  the  Du  Chesne  River,  not  only  the  Uintah  group,  but  both  the 
Green  River  and  Bridger  groups  also,  are  well  developed,  each  possess- 
ing all  its  peculiar  and  usual  characteristics  as  seen  at  the  typical  local- 
ities in  the  great  Green  River  Basin,  north  of  the  Unitah  Mountains. 
This,  added  to  the  known  existence  of  Bridger  strata  in  White  River 
Valley,  and  the  extensive  area  occupied  by  the  Green  River  group  be- 
tween White  and  Grand  Rivers,  has  added  very  largely  to  our  knowledge 
of  the  southward  extension  of  those  formations. 

In  all  the  comparative  examinations  of  the  formations  or  groups  of 
strata  that  have  just  been  indicated,  he  has  paid  especial  attention  to 
their  boundaries,or  planes  of  demarkation,  crossig  and  recrossing  them 
wherever  opportunity  offered,  noting  carefully  every  change  of  both 
lithological  and  paleontological  characters.  While  he  has  been  able  to 
recognize  with  satisfactory  clearness  the  ihree  principal  groups  of  Cre- 
taceous strata,  namely,  the  Dakota,  Colorado,  and  Fox  Hills,  on  both 
sides  of  the  Rocky  and  Uintah  Mountains,  respectively,  they  evidently 
constitute  an  unbroken  series,  so  far  as  their  origin  by  continuous  sedi- 
mentation is  concerned.  While  each  of  the  groups  possesses  its  own 
peculiar  paleontological  characteristics,  it  is  also  true  that  certain  spe- 
cies pass  beyond  the  recognized  boundaries  of  each  within  the  series. 

The  strati  graphical  plane  of  demarkation  between  the  Fox  Hills,  the 
uppermost  of  the  undoubted  Cretaceous  groups,  and  the  Laramie  group, 
the  so-called  Post  Cretaceous,  is  equally  obscure  ;  but  the  two  groups  are 
paleontologically  very  distinct,  inasmuch  as  the  former  is  of  marine  origin, 
while  the  latter,  so  far  as  is  now  known,  contains  only  brackish-water  and 
fresh-water  invertebrate  forms.  He  reports  a  similar  obscurity,  or  ab- 
sence of  a  stratigraphical  plane  of  demarkatiou,  between  the  Laramie 
and  Wasatch  groups,  although  it  is  there  that  the  final  change  from 
brackish  to  entirely  fresh  water  took  place  over  that  great  region.  Fur- 
thermore, he  finds  that  while  the  three  principal  groups  of  the  fresh- 
water Tertiary  series  west  of  the  Rocky  Mountains,  namely,  the  Wasatch, 
Green  River,  and  Bridger  groups,  have  each  peculiar  characteristics, 
and  are  recognizable  with  satisfactory  distinctness  as  general  divisions, 
they  really  constitute  a  continuous  series  of  strata,  not  separated  by 
sharply-defined  planes  of  demarkation,  either  stratigraphical  or  paleou- 
tologicat. 

During  the  progress  of  the  field-work,  as  above  indicated,  large  and 
very  valuable  collections  of  fossils  have  been  made,  all  of  which  will 
constitute  standards  of  reference  in  the  future  progress  of  the  work, 
and  quite  a  large  number  of  the  species  are  new  to  science.  These  are 
now  being  investigated,  and  will  be  published  in  the  usual  paleontological 
reports  of  the  survey. 

Messrs.  S.  H.  Scudder,  of  Cambridge,  and  F.  C.  Bowditch,  of  Boston 
spent  two  months  in  Colorado,  Wyoming,  and  Utah,  in  explorations  for 
fossil  insects,  and  in  collecting  recent  Coleoptera  and  Or  th  opt  era,  espe- 
cially in  the  higher  regions.  They  made  large  collections  of  recent 
insects  at  different  points  along  the  railways  from  Pueblo  to  Cheyenne 
and  from  Cheyenne  to  Salt  Lake,  as  well  as  at  Lakiu,  Kaiis.,  Garland, 
and  Georgetown,  Colo.,  and  in  various  parts  of  the  South  Park  and  sur- 
rounding region. 

For  want  of  time,  they  were  obliged  to  forego  an  anticipated  trip  to 
White  River,  to  explore  the  beds  of  fossil  insects  known  to  exist  there. 
Ten  days  were  spent  at  Green  River  and  vicinity  in  examining  the  Ter- 
tiary strata  for  fossil  insects,  with  but  poor  results;  the  Tertiary  beds  of 
the  South  Park  yielded  but  a  single  determinable  insect,  but  near  Flo- 
51  i 


782     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

rissant  the  Tertiary  basin,  described  by  Mr.  Peale  in  one  of  the  annual 
reports  of  the  survey,  was  found  to  be  exceedingly  rich  in  insects  and 
plants. 

In  company  with  Kev.  Mr.  Lakes,  of  Golden,  Mr.  Scudder  spent  several 
days  in  a  careful  survey  of  this  basin  and  estimates  the  insect-bearing 
shales  to  have  an  extent  at  least  fifty  times  as  great  as  those  of  the 
famous  locality  at  (Eningen  in  Southern  Bavaria.  From  six  to  seven 
thousand  insects  and  two  or  three  thousand  plants  have  already  been 
received  from  Florissant,  and  as  many  more  will  be  received  before  the 
close  of  the  year. 

Mr.  Scudder  was  also  able  to  make  arrangements  in  person  with  par- 
tics  who  have  found  a  new  and  very  interesting  locality  of  Tertiary  strata 
in  Wyoming,  to  send  him  all  the  specimens  they  work  oat,  and  he  con- 
fidently anticipates  receiving  several  thousand  insects  from  them  in  the 
course  of  the  coming  winter.  The  specimens  from  this  locality  are  re- 
markable for  their  beauty.  There  is,  therefore,  every  reason  to  believe 
the  Tertiary  strata  of  the  Eocky  Mountain  region  are  richer  in  remains 
of  fossil  insects  than  any  other  country  in  the  world,  and  that  within  a 
few  months  the  material  at  hand  for  the  elaboration  of  the  work  on  fossil 
insects,  which  Mr.  Scudder  has  in  preparation  for  the  survey,  will  be 
much  larger  than  was  ever  before  subject  to  the  investigation  of  a  single 
naturalist. 

Prof.  Joseph  Leidy,  the  eminent  comparative  anatomist  and  micro- 
scopist,  made  his  second  visit  to  the  West  the  past  season,  under  the 
auspices  of  the  survey.  He  made  a  careful  exploration  of  the  country 
about  Fort  Bridger,  Uintah  Mountains,  and  the  Salt  Lake  Basin,  in 
search  of  rhizopods.  He  has  been  engaged  for  a  long  time  on  a  memoir 
on  this  subject,  which  will  eventually  form  one  of  the  series  of  the  quarto 
Keports  of  the  Survey. 

The  rhizopods  are  the  lowest  and  simplest  forms  of  animals,  mostly 
minute,  and  requiring  high  power  of  the  microscope  to  distinguish  their 
structure.  While  most  of  them  construct  shells  of  great  beauty  and 
variety,  their  soft  part  consists  of  a  jelly-like  substance.  This  the  ani- 
mal has  the  power  of  extending  in  threads  or  finger-like  processes,  which 
are  used  as  organs  of  commotion  and  prehension,  often  branching. 
From  the  appearance  of  their  temporary  organs,  resembling  roots,  the 
class  of  animals  has  received  its  name  of  rhizopoda,  meaning  literally 
root  footed. 

In  compensation  for  the  sraallness  of  these  creatures,  they  make  up 
in  numbers,  and  it  is  questionable  whether  any  other  class  of  animals 
exceed  them  in  importance  in  the  economy  of  nature.  Geological  evi- 
dence shows  that  they  were  the  starting-point  of  animal  life  in  time,  and 
their  agency  in  rock  making  has  not  been  exceeded  by  later  higher  and 
more  visible  forms. 

With  the  marine  kind,  known  as  foraminifera,  we  have  been  longest 
familiar.  The  beautiful  many-chambered  shells  of  these — for  the  most 
part  just  visible  to  the  naked  eye — form  a  large  portion  of  the  ocean- 
iniid  and  the  sands  of  the  ocean-shore.  Shells  of  foraminifera  likewise 
form  the  basis  of  miles  of  strata  of  limestone,  such  as  the  chalk  of  England 
and  the  limestones  of  which  Paris  and  the  pyramids  of  Egypt  are  built. 

Fresh-water  rhizopods,  though  not  so  abundant  as  marine  forms  are 
nevertheless  very  numerous.  They  mainly  inhabit  our  lakes,  ponds,  and 
standing  waters,  but  they  also  swarm  in  sphagnous  swamps  and  ever 
live  in  newest  earth.  Professor  Leidy  has  devoted  several  years  of 
study  to  the  fresh-water  rhizopods  of  the  eastern  portion  of  our  country 
aud  his  especial  object  in  the  past  expedition  was  to  investigate  those 
which  are  to  be  found  in  the  elevated  regions  of  the  Rocky  Mountains 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       783 

The  botany  of  the  Survey  was  represented  the  past  season  by  the  two 
great  masters  of  that  department,  Sir  Joseph  D.  Hooker,  director  of  the 
Gardens  of  Kew,  England,  and  president  of  the  Royal  Society  of  Lon- 
don ;  and  Prof.  Asa  Gray,  of  Cambridge,  Mass.  Their  examinations  ex- 
tended over  a  great  portion  of  Colorado,  Wyoming,  Utah,  Nevada,  and 
California.  Their  investigation  into  the  alpine  floras  and  tree  vegeta- 
tion of  the  Rocky  Mountains  and  Sierra  Nevada  enabled  them  to  give  a 
clear  idea  of  the  relations  and  influence  of  the  climatic  conditions  on 
both  sides  of  the  great  mountain-ranges. 

Sir  Joseph  Hooker,  whose  botanical  researches  embrace  the  greater 
part  of  Europe ;  the  Indies,  from  the  bay  of  Bengal  across  the  Hima- 
laya's to  Thibet;  the  Antarctic  regions  and  the  southern  part  of  South 
America,  New  Zealand,  Australia,  South  Africa,  Morocco  and  Asia 
Minor,  presents  in  the  English  periodical  "Nature"  for  October  25  an 
outline  of  his  studies  during  the  season,  and  this  outline  when  tilled  out 
wi'lform  a  most  important  report  for  the  eleventh  annual  Report  of  the 
Survey.  It  will  be  seen  at  a  glance  that  the  report  will  be  of  the  most 
comprehensive  character,  and  cannot  fail  to  be  of  the  highest  interest 
to  our  people.  The  tree  vegetation,  and  especially  the  conifer&e,  were 
made  special  objects  of  study,  and  many  obscure  points  were  cleared  up. 

Ufa  section  of  the  Rocky  Mountains  comprising  Colorado,  Wyoming, 
and  Utah,  Dr.  Hooker  says: 

Such  a  section  of  the  Rocky  Mountains  must  hence  contain  representatives  of  three 
very  distinct  American  floras,  each  characteristic  of  immense  areas  of  the  continent. 
There  are  two  temperate  arid  two  cold  or  mountain  floras,  viz:  (1)  a  prairie  flora 
derived  from  the  eastward;  (2)  a  so-called  desert  and  saline  flora  derived  from  the 
west;  (3)  a  snbalpine  ;  and  (4)  an  alpine  flora;  the  two  latter  of  widely  different  origin, 
and  in  one  sense  proper  to  the  Rocky  Mountain  ranges. 

The  principal  American  regions  with  which  the  comparison  will  have  first  to  be  in- 
stituted are  four.  Two  of  these  are  in  a  broad  sense  humid  ;  one,  that  of  the  Atlantic 
coast,  and  which  extends  thence  west  to  the  Mississippi  River,  including  tbe  forested 
shores  of  that  river's  western  affluents ;  the  other,  that  of  the  Pacific  side,  from  the 
Sierra  Nevada  to  the  western  ocean  ;  and  two  inland,  that  of  toe  northern  part  of  the 
continent  extending  to  the  Polar  regions,  and  that  of  the  southern  part  extending 
through  New  Mexico  to  the  Cordillera  of  Mexico  proper. 

The  first  and  second  (Atlantic  plus  Mississippi  and  the  Pacific)  regions  are  traversed 
by  meridional  chains  of  mountains  approximately  parallel  to  the  Rocky  Mountains, 
namely,  on  the  Atlantic  side  by  the  various  systems  often  included  under  ti>e  general 
term  appalachian,  which  extend  from  Maine  to  Georgia,  and  on  the  Pacific  side  by  the 
Sierra  Nevada,  which  bound  California  on  the  east.  The  third  and  fourth  of  tbe 
regions  present  a  continuation  of  the  Rocky  Mountains  of  Colorado  and  Utah,  flanked 
for  a  certain  distance  by  an  eastern  prairie  flora  extending  from  the  British  Possessions 
to  Texas,  and  a  western  desert  or  saline  flora,  extending  from  the  Snake  River  to  Ari- 
zona and  Mexico.  Thus  the  Colorado  and  Utah  floras  might  be  expected  to  contain. 
representatives  of  all  the  various  vegetations  of  North  America,  except  the  small  trop- 
ical region  of  Florida,  which  is  confined  to  the  extreme  southeast  of  the  continent. 

The  nxost  singular  botanical  feature  of  North  America  is  unquestionably  the  marked 
contrast  between  its  two  humid  floras,  namely,  those  of  the  Atlantic  plus  Mississippi, 
and  the  Pacific  one;  this  has  been  ably  illustrated  and  discussed  by  Dr.  Gray  in  various 
communications  to  che  American  Academy  of  Sciences,  and  elsewhere,  and  he  has  further 
largely  traced  the  peculiarities  of  each  to  their  source,  thus  laying  the  foundations  for 
all  future  researches  into  the  botanical  geography  of  North  America  ;  but  the  relations 
of  the  dry  intermediate  region  either  to  these  or  to  the  floras  of  other  countries  had  not 
been  similarly  treated,  and  this  we  hope  that  we  have  now  materials  for  discussing. 

Dr.  Hooker  sums  up  the  results  of  the  joint  investigations  of  Dr.  Gray 
and  himself,  aided  by  Dr.  Gray's  previously  intimate  knowledge  of  the 
elements  of  the  American  flora,  from  the  Mississippi  to  the  Pacific  coast : 

That  the  vegetation  of  the  middle  latitudes  of  the  continent  resolves  itself  into  three 
principal  meridional  floras,  incomparably  more  diverse  than  those  presented  by  any 
similar  meridians  in  the  Old  World,  being,  in  fact,  as  far  as  the  trees,  shrubs,  and  many 
genera  of  herbaceous  plants  are  concerned,  absolutely  distinct.  These  are  the  two 
humid  and  the  dry  intermediate  regions  above  indicated. 


784     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR, 

li  of  these,  again,  is  subdivisible  into  three,  as  follows: 

1.  Tin-  Atlantic  slope  ]»lns  Mississippi  region,  subdivisible  into  (a)  an  Atlantic,  (,J) 
a  Mississippi  Valley,  and  (;)  an  interposed  mountain  region  with  a  temperate  and  sub- 
alpiiM-  lloia. 

•J.  'I  !:••  Pacific  slope,  subdivisible  into  (a)  a  very  humid,  cool,  forest-clad  coast  range; 
.  .ir.  hot.  <lr  er  Californian  valley  formed  by  the  San  Juan  River  flowing  to 
Tin-  north  and  the  Sacramento  River  flowing  to  the  south,  both  into  the  Bay  of  San 
rran.-isro:  and  (v)  thr  Sierra  Nevada  flora,  temperate,  subalpine,  and  alpine. 

::.  The  Rocky  Mountain  region,  (in  its  wildest  sense  extending  from  the  Mississippi 
beyond  its  forest,  region  to  the  Sierra  Nevada,)  subdivisible  into  (a)  a  prairie  flora, 
,  desert  or  saline  flora,  (y)  a  Rocky  Mountain  proper  flora,  temperate,  subalpine, 
and  alpine. 

Aft  above^tnted.  the  difference  between  the  floras  of  the  first  and  second  of  these  re- 
gii  ns  is  .sp.-i'ilirally,  and  to  a  great  extent  geuerically,  absolute;  not  a  pine  or  oak, 
maple,  elm,  plane  "or  birch  of  Eastern  America  extends  to  Western,  and  genera  of 
thirty  10  iifry  species  are  confined  to  each.  The  Rocky  Mountain  region  again, though 
abundantly  distinct  from  both,  has  a  few  elements  of  theeastern  region  and  still  more 
of  the  western. 

Many  interesting  facts  connected  with  the  origin  and  distribution  of  American  plants, 
and  the  introduction  of  various  types  into  the  three  regions,  presented  themselves  to 
our  observation  or  our  minds  during  our  wanderings.  Many  of  these  are  suggestive  of 
comparative  study  with  the  admirable  results  of  Heer's  and  Lesquereux's  investiga- 
tions into  the  Pliocene  and  Miocene  plants  of  the  north  temperate  and  frigid  zones, 
arid  which  had  already  engaged  Dr.  Gray's  attention,  as  may  be  found  in  his  various 
publications.  No  less  interesting  are  the  traces  of  the  influence  of  a  glacial  and  a 
warmer  period  in  directing  the  course  of  migration  of  Arctic  forms  Kouthward,  and 
Mexican  forms  northward  in  the  continent,  and  of  the  effects  of  the  great  body  of 
water  that  occupied  the  whole  saline  region  during  (as  it  would  appear)  a  glacial 
period. 

Lastly,  curious  information  was  obtained  respecting  the  a<res  of  not  only  the  big 
trei  s  of  California,  but  of  equally  aged  pines  and  junipers,  which  are  proofs  of  that 
duration  of  existing  conditions  of  climate  for  which  evidence  has  hitherto  been  sought 
raiher  among  fossil  than  among  living  organisms. 

Up  to  the  year  1874  rumor  had  been  telling  many  marvelous  stories 
of  strange  and  interesting  habitations  of  a  forgotten  people,  who  once 
occupied  the  country  about  the  headwaters  of  the  Kio  San  Juan,  but 
these  narrations  were  so  interwoven  with  romance  that  but  few  people 
placed  much  reliance  upon  them.  To  those  well  versed  in  archaeology, 
ruins  of  an  extensive  and  interesting  character  were  known  to  exist 
throughout  New  Mexico  and  Arizona,  and  the  various  reports  of  Abert, 
Johnson,  Sit  greaves,  Simpson,  Whipple,  Newberry,  and  others  form  our 
most- interesting  chapter  in  ancient  American  history;  but  their  re- 
st-arches, aside  from  the  meager  accounts  published  by  .New berry,  throw- 
no  light  on  the  marvelous  cliff  dwellings  and  towns  north  of  the  San 
Juan.  In  187-1  the  photographic  division  of  the  United  States  Geological 
Survey  was  instructed,  in  connection  with  its  regular  work,  to  visit  and 
report  upon  these  ruins,  and  in  pursuance  of  tLis  object  made  a  hasty 
tour  of  the  region  about  the  Mesa  Verde  and  the  toierra  el  Late,  in 
Southwestern  Colorado,  the  results  of  which  trip,  as  expressed  by  Ban- 
croft, in  the  Native  Eaces  of  the  -Pacific  Coast,  "although  made  known, 
to  the  world  only  through  a  three  or  four  days7  exploration  by  a  party 
of  three  men,  are  of  the  greatest  importance.''  A  report  was  made  and 
published,  with  fourteen  illustrations,  in  the  Bulletin  of  the  United 
States  Geological  and  Geographical  Survey  of  the  Territories,  second 
series,  No.  1. 

The  following  year  the  same  region  was  visited  by  Mr.  W.  H  Holmes, 
one  of  the  geologists  of  the  Survey,  and  a  careful  investigation  made  of 
all  the  i  uins.  Mr.  Jackson,  who  had  made  the  report  the  previous  year, 
also  revisited  this  locality,  but  extended  his  explorations  down  the  San 
Jaail  to  the  mouth  of  the  De  Chelly,  and  thence  to  the  Moqui  villages 
in  Northeastern  Arizona.  Returning,  the  country  between  the  Sierra 
Abajo  and  La  Sal  and  the  La  Plata  was  tiaversed,  and  an  immense  nuin- 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       785 

ber  of  very  interesting  ruins  were  first  brought  to  the  attention  of  the 
outside  world  by  the  report  which  was  published  the  following  winter 
by  Messrs.  Holmes  and  Jackson,  in  the  Bulletin  of  the  Survey,  Vol.  II, 
No.  1. 

The  occasion  of  the  centennial  exhibition  at  Philadelphia  led  to  the 
idea  of  preparing  models  of  these  ruins  for  the  clearer  illustration  of 
their  peculiarities,  four  of  which  were  completed  in  season  for  the  open- 
ing of  the  exhibition.  Since  that  time  not  only  the  number  of  these 
interesting  models  has  been  increased,  but  they  have  been  perfected  in 
execution  and  faithful  delineation  of  these  mysterious  remains  of  an 
extinct  race  who  once  lived  within  the  borders  of  our  western  domain. 

A  visit  to  the  rooms  of  Mr.  Jackson,  photographer  of  the  Survey, 
enables  one  to  inspect  in  miniature  size  the  dwellings  of  the  Moqui,  and 
in  full  size  a  large  collection  of  the  ceramics  and  implements  of  those 
ancient  and  extinct  people  of  our  continent.  A  study  of  the  models  will 
give  a  very  excellent  idea  of  the  ruined  dwellings  themselves.  The  first 
of  these  models,  executed  by  Mr.  Holmes,  with  whom  the  idea  originated, 
represents  the  cliff  house  of  the  Mancos  Gallon,  the  exterior  dimensions 
of  which  are  28  inches  in  breadth  by  40  inches  in  height,  and  on  a  scale 
of  1.24,  or  two  feet  to  the  inch.  This  is  a  two-story  building,  constructed 
of  stone,  occupying  a  narrow  ledge  in  the  vertical  face  of  the  bluff  700 
feet  above  the  valley,  and  200  feet  from  the  top.  It  is  24  feet  in  length 
and  14  feet  in  depth,  and  divided  into  four  rooms  on  the  ground-floor. 
The  beams  supporting  the  second  floor  are  all  destroyed.  The  doorways, 
serving  also  as  windows,  were  quite  small,  only  one  small  aperture  in  the 
outer  wall  facing  the  valley.  The  exposed  walls  were  lightly  plastered 
over  with  clay,  and  so  closely  resembled  the  general  surface  of  the  bluff 
that  it  becomes  exceedingly  difficult  to  distinguish  them  at  a  little  dis- 
tance from  their  surroundings. 

The  second  model  of  this  series  was  constructed  by  Mr.  Jackson,  and 
represents  the  large  "cave  town,"  in  the  valley  of  the  Kio  de  Chelly 
near  its  junction  with  the  San  Juan.  This  town  is  located  upon  a  nar- 
row bench,  occurring  about  80  feet  above  the  base  of  a  perpendicular 
bluff  some  300  feet  in  height.  It  is  545  feet  in  length,  about  40  feet  at 
its  greatest  depth,  and  shows  about  75  apartments  on  its  ground-plan. 
The  left-hand  third  of  the  town,  as  we  face  it,  is  overhung  some  distance 
by  the  bluff,  protecting  the  buildings  beneath  much  more  perfectly  than 
the  others.  This  is  the  portion  represented  by  the  model.  A  three- 
story  tower  forms  the  central  feature;  upon  either  side  are  rows  of 
lesser  buildings,  built  one  above  another  upon  the  sloping  floor  of  rock. 
Nearly  all  these  buildings  are  in  a  fair  state  of  preservation.  This  model 
is  37  by  47  inches,  outside  measurements,  and  the  scale  1.72,  or  6  feet  to 
the  inch.  A  "restoration"  of  the  above  forms  the  third  in  the  series,  of 
the  seme  s.ize  and  scale,  and  is  intended,  as  its  name  implies,  to  repre- 
sent as  nearly  as  possible  the  original  condition  of  the  ruin.  In  this  we 
see  that  the  approaches  were  made  by  ladders  and  steps  hewn  in  the 
rock,  and  that  the  roofs  of  one  tier  of  rooms  served  as  a  terrace  for  those 
back  of  them,  showing  a  similarity,  at  least,  in  their  construction  to  the 
works  of  the  Pueblos  in  New  Mexico  and  Arizona.  Scattered  about 
over  the  buildings  are  miniature  representations  of  the  people  at  their 
various  occupations,  with  pottery  and  other  domestic  utensils. 

The  u  triple- walled  tower,'7  at  the  head  of  the  McElmo,  is  the  subject 
of  the  fourth  model.  It  was  constructed  by  Mr.  Holmes,  and  represents, 
as  indicated  by  its  title,  a  triple-walled  tower,  situated  in  the  midst  of 
a  considerable  extent  of  lesser  ruins,  probably  of  dwellings,  occupying 


786     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

a  low  bench  bordering  the  dry  wash  of  the  McElmo.  The  tower  is  42 
feet  in  diameter,  the  wall  2  feet  thick,  and  now  standing  some  12  feet 
hi«>h.  The  two  outer  walls  inclose  a  space  of  about  li  feet  in  width, 
which  is  divided  into  14  equally-sized  rooms,  communicating  with  one 
another  by  smal  window-like  doorways.  The  next  is  a  "cliff-house"  m 
the  valley  of  the  Kio  <!e  Chelly.  It  is  about  20  miles  above  the  cave 
town  Mhv'ady  spoken  of.  This  is  a  two-story  house,  about  20  feet  square, 
occupying  a'  ledge  some  75  feet  above  the  valley,  and  overhung  by  the 
bluff.  *  The  approach  from  the  valley  is  by  a  series  of  steps  hewn  m  the 
steep  luce  of  the  rock;  and  this  method  was  the  one  most  used  by 
the  occupants,  although  there  is  .-•  way  out  to  the  top  of  the  bluff. 
'1  his  model  is  42  inches  in  height  by  24  broad,  and  is  built  upon  a  scale 
of  1 .30. 

Te*wa,  one  of  the  seven  Moqui  towns  in  Northeastern  Arizona,  is  a 
very  interesting  and  instructive  model,  representing,  as  it  does,  one  of 
the' most  ancient  and  best  authenticated  of  the  dwellings  of  a  people 
who  Hie  supposed  to  be  the  descendants  of  the  cliff  dwellers.  Tewa  is 
the  first  of  The  seven  villages  forming  the  province  as  we  approach 
them  Irom  the  east,  and  occupies  the  summit  of  a  narrow  mesa  some 
COO  feet  in  height  and  1,200  yards  in  length,  upon  which  are  also  two 
other  somewhat  similar  villages.  The  approach  is  by  a  circuitous  road- 
way hewn  in  the  perpendicular  face  of  the  bluff,  which  surrounds  the 
mesa  upon  all  sides.  Jt  is  the  only  approach  accessible  for  animals  to 
the  three  villages.  Other  ladder-like  stairways  are  cut  in  the  rock, 
which  are  used  principally  by  the  water  carriers,  for  all  their  springs 
and  reservoirs  are  at  the  bottom  of  the  mesn.  This  village  is  represented 
upon  a  scale  of  1  inch  to  8  feet,  or  1.96.  The  dimensions  of  the  model 
are  ,'50  inches  in  length,  29  inches  in  width,  and  14  inches  in  height. 

Jn  the  spring  of  1877,  Mr.  Jackson  made  a  tour  over  much  of  the 
northern  part  of  New  Mexico,  and  westward  to  the  Moqui  towns  in 
Arizona,  mid  secured  materials  for  a  number  of  very  interesting  models, 
illustrating  the  methods  of  the  Pueblos  or  town-builders  in  the  con- 
struction of  their  dwellings.  Two  villages  have  been  selected  for  imme- 
diate construction,  as  showing  the  most  ancient  and  best  known  exam- 
ples of  their  peculiar  architecture,  viz,  Taos  and  Acoma  ;  the  one  of 
many-storied,  terraced  houses,  and  the  other  built  high  up  on  an  impregna- 
ble rock.  The  model  of  Taos  is  now  completed,  the  dimensions  of  which 
are  42  by  39  inches,  and  the  scale  one  inch  to  twenty  feet,  1 : 240. 

Of  this  town  Davis  says: 

It  is  the  best,  sample  of  the  ancient  mode  of  building.  Here  are  two  large  houses 
lint e  or  four  hundred  feet  in  length,  and  about  one  hundred  and  fifty  feet  wide  at  the 
b;ise.  They  are  situated  upon  opposite  sides  of  a  small  creek,  and  in  ancient  times 
juv  said  to  have  been  connected  with  a  bridge.  They  are  five  and  six  stories  high, 
each  story  receding  from  tbeoi.e  below  it,  and  thus  forming  a  structure  terraced  from 
t<>p  to  bottom.  Each  story  isdivided  into  numerous  little  compartments,  the  outer  tier 
of  rooms  being  lighted  by  small  windows  in  the  sides,  while  those  in  the  interior  of  the 
bnihl ing  are  dark,  and  are  principally  used  as  storerooms.  *  *  *  The  only  means 
of  entrance  is  tlnough  a  trap-door  in  the  roof,  and  you  ascend  from  story  to  story  by 
means  of  ladders  ou  the  outside,  which  are  drawn  up  at  night. 

Their  contact  with  Europeans  has  modified  somewhat  their  ancient 
style  of  buildings,  principally  in  substituting  doorways  in  the  walls  of 
iheir  houses  for  those  in  the  roof.  Their  modern  buildings  are  rarely 
over  two  stories  in  height,  and  are  not  distinguishable  from  those  of 
their  Mexican  neighbors.  The  village  is  surrounded  by  an  adobe  wall, 
which  is  first  included  within  the  limits  of  the  modelj  and  incloses  an 
area  of  eleven  or  twelve  acres  in  extent.  Within  this  limit  are  four  of 
their  estufas,  or  secret  council-houses.  These  are  circular  underground 


GEOLOGICAL   SURVEY    OF    THE    TERRITORIES.  787 

apartments,  with  a  narrow  opening  in  the  roof,  surrounded  by  a  pali- 
sade, ladders  being  used  to  go  in  and  out. 

These  models  are  first  carefully  built  up  in  clay,  in  which  material  all 
the  detail  is  readily  secured,  and  are  then  cast  in  plaster,  a  mold  being 
secured  by  which  they  are  readily  multiplied  to  any  extent.  They  are 
then  put  in  the  hands  of  the  artists  and  carefully  colored  in  solid  oil 
paints  to  accurately  resemble  their  appearance  in  nature,  and,  in  the 
case  of  restorations  or  modern  buildings,  all  the  little  additions  are  made 
which  will  give  them  the  appearance  of  occupation.  The  survey  is  in 
possession  of  the  data  for  the  construction  of  many  more  models,  and 
they  will  be  brought  out  as  opportunity  is  given.  They  have  also,  in 
connection  with  the  views,  multiplied  many  of  the  curious  pieces  of  pot- 
tery which  have  been  brought  back  from  that  region  by  the  various 
parties  connected  with  the  survey. 

During  the  season  of  1877  it  was  found  impracticable  to  place  a  sepa- 
rate party  in  the  field  for  zoological  work,  as  Dr.  Elliott  Coues,  the 
naturalist  of  the  Survey,  was  fully  occupied  during  the  summer  at  the 
Washington  office  in  the  care  of  the  numerous  publications  of  the  Sur- 
vey which  have  appeared  during  the  present  year. 
Very  respectfully,  your  obedient  servant, 

Y.  V.  HAYDEN, 

United  States  Geologist. 
Hon.  CARL  SCHUKZ, 

^'Secretary  of  the  Interior,  Washington,  D.  C. 


PRELIMINARY  REPORT 

OF   THE 


FIELD  WORK  OF  THE  UNITED  STATES  GEOLOGICAL  AND  GEO- 
GRAPHICAL SURVEY  OF  THE  TERRITORIES  FOR  THE  SEASON 

OF  1878. 


BvF.  V.  HAYDEX. 


OFFICE  GEOLOGICAL  AND  GEOGRAPHICAL 

SURVEY  OF  THE  TERRITORIES, 

Washington,  I).  C.,  December  1,  1878. 

SIR  :  I  have  the  honor  to  present  for  your  consideration  a  brief  sum- 
mary of  the  field  work  of  the  United  States  Geological  and  Geographical 
Survey  under  my  charge,  for  the  season  of  1878. 

Owing  to  the  length  of  the  session,  Congress  did  not  pass  the  usual 
appropriation  for  the  work  of  the  survey  until  July,  and  consequently 
the  field  labor  was  of  comparatively  short  duration. " 

The  headquarters  of  the  survey  was  at  Cheyenne,  Wyo.,  the  same  as 
the  preceding  season.  Four  parties  were  organized,  butni  such  a  manner 
that  in  case  of  necessity  they  could  be  divided  for  special  duty.  All  our 
outfit  and  animals  Avere  transported  from  Cheyenne  to  Point  of  Rocks 
and  Green  River  Stations,  on  the  Union  Pacific  Railroad,  and  from  thence 
the  parties  pursued  their  way  northward  to  their  respective  fields  of 
labor. 

To  the  first  division,  in  .charge  of  A.  D.  Wilson,  was  confided  the  pri- 
mary triangulatioii  of  the  entire  area  to  be  surveyed.  Eight  of  the 
most  important  peaks  were  employed  as  stations,  with  some  minor 
points.  Among  the  more  important  stations  were  Wind  River,  Fre- 
mont's, Gxand  Teton,  and  SawteUe?s  Peaks  (near  Henry's  Lake); 
also  several  of  the  most  conspicuous  points  in  the  Yellowstone  Park. 
This  division  was  robbed,  near  Sawtelle's  Peak,  of  all  its  animals  and  a 
portion  of  its  outfit,  so  that  at  least  half  of  the  most  valuable  time  for 
work  during  the  season,  was  lost.  Had  it  not  been  for  this  misfortune 
at  least  double  the  work  would  have  been  accomplished.  The  Yellow- 
stone Park  at  this  time  forms  the  most  extensive  unoccupied  area  in  the 
West,  and,  surrounded  by  great  ranges  of  mountains,  becomes  a  resor£ 
for  hostile  bands  of  Indians  when  pursued  by  the  troops. 

To  the  division  of  the  survey  in  charge  of  Mr.  Henry  Gannett  was  in- 
trusted the  work  of  making  a  specially-detailed  geological  and  geograph- 
ical survey  of  the  Yellowstone  National  Park.  The  party  was  divided 
into  two  sections  for  the  prosecution  of  this  work ;  one  section,  consist- 
ing essentially  of  Mr.  Gannett,  topographer,  and  Mr.  W.  H.  Holmes, 
geologist,  made  the  general  survey  of  the  park,  while  the  other,  consist- 
ing of  Dr.  A.  C.  Peale  and  Mr.  J.  E.  Mushbach,  were  occupied  in  mak- 
ing detailed  studies  and  maps  of  the  geyser  and  hot-spring  localities,  a 
work  of  the  greatest  interest  and  value  to  the  scientific  world. 

Material  was  secured  for  a  detailed  map,  on  a  scale  of  one  mile  to  an 
inch,  of  the  Yellowstone  Park,  an  area  of  3,500  square  miles ;  and  for 
maps  on  a  large  scale  of  all  the  principal  geyser  and  hot-spring  locali- 


952     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

tics.  In  the  survey  of  the  park,  forty-seven  important  stations  were 
oreupied  tor  secondary  triangtdation  and  topography,  besides  a  large 
numU'i -oriesser  importance;  On  all  the  principal  stations,  stone  monu- 
ments were  erected  tor  future  reference.  Several  groups  ot  geysers  and 
hoi  >piin-s.  not  heretofore  known,  were  discovered. 

Tin-  area  of  the  Yellowstone  Park  is,  in  round  numbers,  3,aOO  square 
miles.  Its  surface  is  in  large  part  level  or  rolling,  with  several  groups 
and  short  ranges  of  mountains  diversifying  it.  In  the  eastern  part, 
extending  its  whole  length  and  forming  the  Avater-shed  between  the 
Yellowstone  and  the  Bighorn,  stand  the  rugged  volcanic  peaks  of  the 
Yellowstone  Raime.  Nearly  all  of  the  park  is  covered  with  a  dense 
month  of  magnificent  pine  timber;  indeed,  west  of  the  one  hundredth 
meridian  there  is  no  area  so  densely  timbered  with  the  exception  of  Wash- 
ington Territory.  The  mean  elevation  of  the  park  above  sea-level  is  be- 
tween 7,000  and  8,000  feet,  which  implies  too  cold  a  climate  to  admit  of 
agriculture,  except  in  certain  very  limited  localities.  It  is  safe  to  say 
that  not  more  than  one  per  cent,  of  this  area  can,  by  any  possibility,  be 
used  for  agricultural  purposes.  Except  along  the  northern  border, 
grazing  land  exists  only  in  small  patches  of  a  lew  acres  each.  There 
are  not,  so  far  as  is  known,  any  mines  or  mineral  deposits  within  the 
park. 

The  only  occupied  buildings  within  the  park  are  at  the  White  Mount- 
ain Hot  Springs,  where  Mr.  J.  C.  McCartney  has  made  some  improve- 
ments. A  good  wagon-road  extends  from  Bozeniau,  Mont.,  to  this  point. 
From  these  spring*;  which  form  the  usual  point  of  departure  for  excur- 
sionists, there  are  excellent  trails  to  all  points  of  interest  within  this 
region ;  to  Amethyst  Mountain,  Yellowstone  Falls  and  Lake,  the  Mud 
(leysers,  and  other  objects  of  interest  on  Yellowstone  Eiver  and  the 
Geyser  Basins.  It  is  unnecessary  to  specify  these  trails,  as  they  traverse 
the  country  in  all  directions.  In  his  campaign  against  the  Nez  Perees, 
in  1S77,  General  Howard  constructed  an  excellent  wagon-road  up  the 
Madison  to  the  Lower  Geyser  Basin,  and  thence  across  to  the  Yellow- 
stone. His  road  up  the  YelloAvstone  is  impassable  at  present  for  wagons. 

Mr.  W.  H.  Holmes  acted  as  geologist  to  the  second  division.  The 
first  month  of  the  season  he  was  wiih  the  fourth  division,  which  pro- 
ceeded from  Point  of  Rocks  Station  northward,  along  the  west  side  of 
the  Wind  Eiver  Mountains,  and  up  the  Snake  Eiver  Valley  to  the  Yel- 
lowstone Park,  where  he  joined  the  second  division.  In  the  mean  time 
he  was  engaged  in  making  sketches,  panoramic  views,  and  geological 
sections  of  the  intermediate  country,  all  of  which  will  prove  of  the 
highest  importance  in  illustrating  the  geological  structure  of  this  most 
interesting  and  complicated  region. 

The  latter  part  of  the  summer  was  spent  in  making  detailed  geological 
examinations  in  the  district  that  includes  the  National  Park.  The  greater 
portion  of  the  park  was  found  to  be  covered  with  somewhat  uniform 
flows  of  the  ordinary  volcanic  rocks.  Features  of  more  than  ordinary 
geologic  interest  occur,  however,  along  the  northern  border  of  the  park 
district.  Here  a  small  belt,  not  more  than  15  by  30  miles  in  extent,  con- 
tains a  fair  epitome  of  the  geology  of  the  Eocky  Mountain  region.  The 
whole  series  of  formations  from  the  earliest  to  the  most  recent  are  almost 
typically  developed.  The  only  marked  irregularity  in  the  succession  of 
geologic  events  occurred  during  the  great  mountain-building  period  of 
t  he  M  iddle  Tertiary.  After  that  followed  a  number  of  inferior  oscillations 
of  the  sin-face,  during  which  an  extensive  series  of  recent  Tertiary  and 
volcanic  rocks  were  deposited.  Connecting  this  period  with  the  present 
are  the  deposits  of  a  number  of  great  lakes,  which  at  the  present  time 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       953 

have  their  chief  representative  in  Yellowstone  Lake.  Detailed  investi- 
gations were  made  at  many  points  of  interest,  and  a  fine  mineralogical 
collection  was  made. 

In  the  mean  time  Mr.  Holmes  sketched  every  square  mile  of  the  park, 
an  area  of  3,500  square  miles.  In  such  minute  detail  was  the  work  done 
that  the  economic  resources,  as  well  as  all  the  minor  features  of  the  geol- 
ogy, can  be  laid  down  on  a  map  on  a  scale  of  one  mile  to  an  inch  Avith 
the  greatest  care  and  minuteness.  The  great  variety  of  forms  which 
the  mountains  in  and  around  the  park  assume  can  be  presented  to  the 
eye  by  panoramic  views  with  wonderful  distinctness. 

The  third  division,  under  Mr.  E.  A.  Clark,  surveyed  the  Wind  River 
Mountains,  a  portion  of  the  Wyoming  Range,  the  Gros  Ventres  Range, 
with  a  large  area  in  the  Snake  River  Valley.  Mr.  Clark  made  31  gradi- 
enter  stations  and  15  compass  stations.  The  area  lies  between  latitude 
43°  and  44°  and  longitude  109°  15'  and  111°.  This  includes  the  upper 
portion  of  the  Wind  River  Mountains,  Avith  portions  of  the  Wyoming 
n  ling  Range,  the  Gros  Ventres  Range,  and  portions  of  the  Shoshone 
Mountains  and  the  Owl  Creek  Range  ;  also  the  sources  of  Green  River, 
Hoback  Basin,  and  upper  Avaters  of  Wind  River.  Mr.  St.  John  acted  as 
geologist  and  Mr.  N.  W.  Perry  as  mineralogist  to  this  party.  Their 
reports  wrill  prove  of  general  interest.  Mines  of  gold,  silver,  iron,  and 
vast  beds  of  gypsum,  as  Avell  as  many  other  minerals,  Avere  found. 

In  the  prosecution  of  the  field- work  of  the  survey  during  the  past 
season  a  photographic  division  was  again  put  in  operation,  after  an 
interval  of  two  years,  under  the  leadership  of  Mr.  W.  II.  Jackson,  who 
has  been  connected  with  the  survey  as  its  photographer  during  the  past 
nine  years. 

Leaving  Point  of  Rocks,  on  the  Union  Pacific  Railroad,  on  July  24, 
the  first  points  of  interest  Avere  reached  on  the  western  flank  of  the 
Wind  RiATer  Mountains.  Two  side  trips,  undertaken  in  connection  with 
Mr.  Wilson,  in  charge  of  the  primary  triangulation,  AA~ere  made  to  the 
crest  of  the  range,  and  some  grand  views  of  that  remarkable  region 
were  obtained.  From  the  summit  of  Fremont's  Peak  ArieAArs  Avere  made 
of  an  immense  glacier  IIOAV  occupying  its  eastern  slope.  Fine  views 
were  also  obtained  of  the  great  glaciated  plateau  lying  between  the 
plains  and  the  crest  of  the  range. 

Proceeding  next  to  the  vicinity  of  the  Grand  Tetons,  lying  to  the  east 
of  the  headAvaters  of  the  Snake  RiA^er,  seA7eral  magnificent  AdeAvs  of  the 
remarkable  range  in  Avhich  they  occur  AArere  made  from  the  neighborhood 
of  Jackson's  Lake. 

Reaching  Shoshone  Lake  the  18th  of  August,  the  entire  month  folloAV- 
ing  AAras  deAroted  exclusively  to  the  careful  photography  of  all  the  remark- 
able phenomena  connected  Avith  the  hot  springs  and  geysers  of  the  various 
basins  Avithiii  the  Park.  Especial  attention  was  paid  to  the  almost  un- 
known but  exceedingly  interesting  features  of  the  new  Shoshoue  and 
Red  Mountain  Basins.  The  uFire  Hole"  and  ''Mammoth  Hot  Spring" 
Basins  Avere  again  gone  over,  and  the  experience  derived  from  the  work 
done  here  in  former  years  shoAvs  its  benefits  in  the  remarkably  eifectiAre 
ATiews  obtained  this  season.  At  this  latter  basin  many  detailed  as  Aveli 
as  general  ATieAvs  were  ma"de  with  especial  reference  to  the  future  pro- 
duction of  an  exact  model  in  plaster  of  the  whole  group. 

On  the  homeward  route,  AA'hich  was  by  the  way  of  the  Upper  Yellow- 
stone, across  the  headwaters  of  the  Snake  to  the  Wind  River  and  thence 
A'ia  Camp  Brown  to  the  railroad,  a  number  of  A7ery  effective  views  were 
made,  particularly  about  the  Grand  Falls  and  the  canon  of  the  Yellow- 
stone. At  the  Yellowstone  Lake  some  very  fine  vieAvs  Avere  made,  but 


954     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

that  region  was  left  somewhat  incomplete  in  consequence  of  a  prolonged 
snow-storm.  ,  ,    .      ^     ,.,, 

As  the  To«-wotee  Pass  some  characteristic  views  were  obtained  ot  tne 
remarkable  breccia  mountains,  whose  castellated  forms  adorn  that  por- 
tion ofthe  continental  divide,  and  also  some  of  the  curious  «  bad  lands  » 
ini  t  her  down  on  Wind  River.  The  season's  work  closed  at  Camp  Brown, 
^  here  some  excellent  portraits  and  groups  were  made  of  the  Bannock 
prisoners  in  confinement  at  that  post. 

V  brief  summing  up  of  the  season's  operations  of  three  months,  much 
Of  which  time  was  characterized  by  extremely  inclement  weather,  shows 
an  increase  to  the  already  very  extensive  collection  of  the  survey,  ot  4o 
negatives  11  by  14  inches  in  size,  and  110  of  smaller  ones,  5  by  8.  The 
number  was  purposely  kept  small  that  a  better  quality  might  prevail  111 

The  geologist  in  charge  accompanied  the  photographic  division,  and 
the  route  pursued  gave  him  an  opportunity  to  secure  a  very  accurate 
general  knowledge  of  the  geological  structure  of  a  large  area.  The 
Wind  River  Range  proved  one  of  remarkable  interest.  It  has  a  trend 
about  northwest  and  southeast,  with  a  length  of  about  100  miles.  On 
the  west  side  all  the  sedimentary  belts  have  been  swept  away,  down  to 
the  Arcluean,  older  than  the  Wahsatch,  and  the  latter  formation  rests  on 
the  Archaean  rocks  all  along  the  base  of  the  range,  seldom  inclining  more 
than  5°  to  10°.  On  the  east  side  of  the  range  the  seams  of  sedimentary 
formations  usually  known  to  occur  in  the  northwest  are  exposed  from 
the  Potsdam  sandstone,  which  rests  upon  the  Archsean  rocks,  to  the  Cre- 
taceous inclusive. 

Along  the  northwestern  portion  of  the  range  the  Wahsatch  Group  only 
is  seen  for  some  distance,  but  as  we  proceed  down  the  Wind  River 
Valley  the  formations  appear  one  after  the  other,  until  at  the  lower  end 
the  entire  series  is  exposed.  The  Wind  River  Range  may  be  regarded 
as  originally  a  vast  anticlinal,  of  which  one  side  has  been  entirely 
denuded  of  the  sedimentary,  except  the  Middle  Tertiary.  On  the  same 
side  of  the  range  the  moraiiial  deposits  and  glaciated  rocks  are  shown 
on  a  scale  such  as  we  have  not  known  in  any  other  portion  of  the  West. 
Three  genuine  glaciers  were  discovered  on  the  east  base  of  Wind  River 
and  Fremont  Peaks,  the  first  known  to  exist  east  of  the  Pacific  coast. 

The  moraiiial  deposits  are  also  found  on  a  grand  scale  in  the  Snake 
River  Valley,  on  the  east  side  of  the  Teton  Range.  The  numerous  lakes 
have  been  the  beds  of  glaciers,  and  the  shores  of  the  lakes  are  walled 
with  morainal  ridges.  ^North  of  the  Teton  Mountains  the  prevailing 
rocks  are  of  modern  volcanic  origin,  and  in  the  Yellowstone  Park  the, 
hot  springs  and  geysers  are  the  later  manifestations  of  the  intense  vol- 
canic activity  that  once  existed.  All  these  interesting  features  were 
studied  with  care,  and  the  results  Avill  be  elaborated  for  the  twelfth  an- 
nual report  of  the  survey. 

1 1  was  with  great  pleasure  that  the  geologist  in  charge  reviewed  the 
ground  passed  over  in  I860,  over  eighteen  years  previously.  In  the 
years  is.V.J  and  1860  he  acted  as  geologist  to  the  exploring  expedition 
under  the  command  of  Col.  William  F.  Raynolds,  now  of  the  Engineer 
( 'orps,  IT.  S.  A.  A  portion  of  the  geological  "report  made  on  that  expe- 
dition  will  be  reprinted  in  the  llth  annual  report.*  A  geological  map 
accompanies  this  report,  which  embraces  Dakota  and  Montana,  with 
portions  of  Idaho,  Wyoming,  and  Colorado. 

•<;(-olooi(.al  Report  of  the  Exploration  of  the  Yellowstone  and  Missouri  Rivers, 
under  tin-  direction  of  dipt,  (now  Lieut.  Col.  and  Brevet  Bri"1.  Gen  )  W  F  Ravnolds 
Corps  of  Engineers,  1859-1860.  By  F.  V.  Hayden. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       955 

The  publications  of  the  survey  during  the  past  year  have  been  numer- 
ous and  important.  The  atlas  of  Colorado,  in  twenty  sheets,  has  received 
the  most  unqualified  praise  for  its  accuracy  and  beauty,  both  in  this 
country  and  in  Europe.  The  following  analysis  of  the  atlas  was  written 
for  the  London  periodical  "Nature,"  of  September  12,  by  Prof.  Archi- 
bald Geikie,  director  of  the  geological  survey  of  Scotland  and  professor 
of  geology  in  the  University  of  Edinburgh,  and  one  of  the  ablest  geol- 
ogists in  Europe : 

In  the  magnificent  atlas  just  issued  by  the  Department  of  the  Interior  we  have  the 
consummation  and  crown  of  all  the  labors  which  Dr.  Haydeii  and  his  staff  have  carried 
on  so  triumphantly  for  the  last  five  years,  and  of  which  they  have  already  given  us  so 
much  interesting  and  important  information  in  a  series  of  annual  reports.  Before  ex- 
amining the  work  from  a  scientific  point  of  view,  no  reader  can  refrain  from  expressing 
his  admiration  of  the  style  in  which  the  atlas  has  been  produced  by  the  United  States 
Government.  As  a  specimen  of  cartography,  typography,  and  lithography  it  is  alto- 
gether worthy  of  the  highest  praise.  For  beauty  and,  indeed,  sumptuousness  of  exe- 
cution, it  may  be  classed  with  those  livres  tie  luxe  which  from  time  to  time  have  been 
issued  from  the  National  Imprimerie  of  France. 

The  atlas  consists  of  two  series  of  maps,  the  one  of  a  general,  the  other  of  a  detailed 
kind.  The  first  series,  on  the  scale  of  twelve  miles  to  one  inch,  comprises  four  sheets, 
each  embracing  the  whole  State  of  Colorado  and  part  of  the  neighboring  territory. 
The  first  of  these  illustrates  the  system  of  triaiigulation  adopted  in  the  survey ;  the 
second  shows  the  drainage  system  of  the  area ;  the  third,  by  a  simple  and  clear  arrange- 
ment of  colors,  exhibits  at  a  glance  the  economic  features  of  the  whole  region — the  ag- 
ricultural land,  pasturage,  forests  and  woodlands,  sage  and  bad  lands,  mineral  tracts, 
and  the  portions  rising  above  the  limit  of  timber-growth;  the  fourth  contains  a  con- 
densed and  generalized  geological  map  of  the  same  territory.  Nothing  can  surpass  the 
lucidity  of  expression  and  artistic  finish  of  these  maps. 

The  second  series — twelve  in  number — is  on  the  scale  of  four  miles  to  one  inch,  and 
consists  of  six  topographical  sheets  and  six  identical  sheets,  colored  geologically.  The, 
topographical  details,  though  numerous,  are  so  selected  as  not  to  neutralize  each  other 
or  mar  the  broad,  clear  picture  which  the  maps  were  designed  to  be.  By  means  of 
contour-lines  of  %00  feet  vertical  distance,  the  surface-configuration  of  the  whole  region 
is  depicted  as  in  a  model.  We  can  follow  the  lines  of  the  broad  valleys,  of  the  deep, 
narrow  canons,  and  of  the  hundreds  of  minor  tributaries  which  have  scarped  out  their 
courses  on  either  side.  Here  we  look  down  upon  a  vast  table-land,  deeply  trenched  by 
stream-channels;  there  upon  a  succession  of  bold  escarpments  or  mesas,  which  bound 
the  table-laud  and  hem  in  the  neighboring  valley.  Huge  mountain-ranges  rising  out 
of  the  plateaus  are  so  vividly  drawn  that  they  seem  to  stand  out  of  the  paper;  yet 
no  shading  is  employed.  All  the  effects  of  inequality  are  produced  by  contour  lines, 
so  faithfully  set  down  that  a  single  line  may  be  tracked  in  its  sinuous  course  along  the 
whole  of  a  mountain  front  until  it  comes  out  upon  the  table-land  beyond.  When  will 
our  map-makers  learn  to  use  this,  the  only  true  method  for  expressing  the  surface  of  a 
country  ?  The  best  of  our  atlases  are  disfigured  by  strips  of  shading  running  across  the 
map,  like  so  many  caterpillars,  to  represent  mountain  ranges.  Even  our  ordnance 
maps,  so  admirable  in  most  respects,  are  sometimes  so  loaded  with  shading  that  a  steep 
hillside,  only  a  few  hundred  feet  high,  is  made  as  black  as  our  highest  mountains,  and 
the  topographical  names  can  hardly  be  read,  even  with  a  magnify  ing-glass. 

But,  above  all,  welcome  are  these  six  geological  maps.  In  the  previously  published 
maps  and  charts  accompanying  the  annual  reports  only  small  detached  areas  were 
represented,  and  even  from  the  careful  descriptions  of  the  various  geologists  of  the 
staff,  it  was  hardly  possible  to  frame  a  satisfactory  conception  of  the  geology  of  Col- 
orado as  a  whole.  Ever  since  the  marvels  of  its  deep  gorges  and  vividly  painted  cliffs 
were  made  known,  that  region  has  possessed  a  high  interest  to  the  geologist.  He  has 
now  the  means  of  gratifying  his  desire  for  further  knowledge.  With  the  help  of  these 
maps  and  the  two  accompanying  sheets  of  sections,  he  can  realize  most  satisfactorily 
every  great  feature  of  Colorado  geology.  The  ancient  Archaean  ridge — the  nucleus  or 
backbone  of  the  American  Continent — may  be  traced  running  north  and  south  nearly 
along  the  present  hydrographical  axis  of  the  country.  Flanking  that  ridge  comes  a 
series  of  Palsezoic  deposits,  the  oldest  of  which  have  been  identified  paheontologically 
with  Silurian  formations.  Rocks  regarded  as  of  Devonian  age  overlap  the  Silurian 
beds,  and  repose  against  the  ancient  crystalline  ridge  on  the  southwest  side  of  the 
San  Juan  Mountains.  They  are  soon  buried  under  later  accumulations,  and  they 
seem  to  be  of  but  local  development,  since  in  most  places  where  the  rocks  are  found 
in  juxtaposition,  the  Silurian  are  directly  succeeded  by  Carboniferous  strata.  These 
last-named  rocks  cover  largo  tracts  of  country,  running  as  bands  round  the  Archaean 
area,  and  lying  in  basins  across  it.  Far  to  the  west,  where  the  Grand  River  has  so 
deeply  trenched  the  Utah  plateau,  the  flat  Carboniferous  beds  appear  from  under  the 


956     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

brilliant  iv. 1  Triassir  strata.  The  difficulty  of  drawing  any  line  between  Triassic  and 
Jurassic  formations  in  thai  region  is  again  acknowledged  on  these  maps,  the  lower 
ivd  aeriea  l.eiug  doubtfully  assigned  to  the  older,  and  the  upper  variegated  deposits  to 
the  latter  system. 

CreUoeous  rocks  arc  abundantly  developed,  and  cover  a  vast  extent  of  territory. 
In  particular,  they  spread  over  tlie  wide  plateaux  between  the  San  Juan  and  Guimison 
Ki\eis.  and  form 'the  platform  on  which  the  enormous  volcanic  outbursts  have  been 
piled  up  from  the  West  Elk  Mountains  southward  into  New  Mexico.  It  is  more  easy 
t..  n.iee  on  these  maps,  too,  the  area  respectively  occupied  by  the  Laraniie,  Wa- 
sateh.  (Jiveu  River,  I'.ridger,  and  T'intali  formations  which  represent  Post  Cretaceous 
and  Tertiary  times.  Glacier  moraines,  lake  deposits,  drifts,  sand-dunes,  and  recent 
alluvia,  all  iind  adequate  expression  on  the  maps.  Especial  care,  too,  seems  to  have 
been  bestowed  upon  the  eruptive  rocks  which  form  so  important  and  interesting  a 
feature  of  Colorado  geology.  The  more  characteristic  varieties  are  represented  by 
distiuet  shades  of  crimson  or  orange,  and  they  have  been  mapped  in  such  a  way  as  to 
eonvey  at  a  glance,  and  even  without  the  aid  of  sections,  a  tolerable  clear  notion  of 
the  volcanic  phenomena  of  the  region.  On  the  one  hand  we  see  the  great  lava-sheets 
capping  the  mesas  and  spreading  far  over- the  plateaux;  on  the  other,  we  notice  the 
meat  centres  of  volcanic  activity,  with  their  abundant  flows,  dikes,  and  breccias. 

1  \\  o  sheets  of  sections,  drawn  across  all  the  more  interesting  and  important  portions 
of  the  geology,  complete  the  vast  fund  of  information  given  by  the  maps;  while,  that 
nothing  may  he  wanting  to  enable  readers  to  realize  what  has  been  done  by  the  sur- 
\ey.  and  the  conditions  under  which  it  has  been  accomplished,  two  large  sheets  of 
sketches  are  given,  which  most  vividly  represent  the  forms  of  the  mountains,  plateaux, 
mesas,  and  river  channels  as  seen  from  various  commanding  heights. 

Dr.  Hayden,  with  whose  personal  supervision  this  great  work  has  been  accomplished, 
has  increased  tenfold  the  obligations  under  which  he  has  laid  geologists  all  over  the 
world  for  Ihe  number  and  value  of  his  contributions  to  geology.  He  now  furnishes  us 
with  new  light  whereby  to  read  his  former  researches  and  those  of  his  able  colleagues. 
M  ay  we  venture  to  hope  that  he  may  find  leisure  to  confer  yet  one  further  benefit  before 
t  he  progress  of  his  survey  plunges  him  into  a  new  whirl  of  work  ?  If  he  could  be  pre- 
vailed upon  to  sketch  out  a  plan  for  digesting  the  materials  of  his  published  annual 
reports,  he  could  doubtless  find  among  his  staff  some  competent  writer  who,  under  his 
guidance,  could  produce  a  well-arranged  systematic  guide-book  or  text-book  to  com- 
plete the  value  of  the  work  of  his  survey.  Such  a  book  of  reference's  would  give  a 
leader  who  has  never  had  access  to  the  annual  reports  a  clear  and  comprehensive  view 
of  ( 'olorado  geology  would  be  of  great  service. 

These  remarks  may  be  fitly  closed  with  an  expression  of  the  warmest  admiration  of 
the  liberal  spirit  in  which  the  United  States  Government  has  conducted  these  surveys 
of  the  Territories  and  has  published  their  results.  This  costly  atlas  has  been  distrib- 
uted gratuitously  all  over  Europe.  That  this  is  a  wise  policy  cannot  be  doubted. 
Whether  actuated  or  not  by  a  desire  to  diffuse  scientific  information,  the  authorities 
at  Washington  do  well  to  make  as  widely  known  as  possible  the  geological  structure 
and  economic  resources  of  their  country.  They  cast  their  bread  upon  the  waters  and 
the  harvest  comes  to  them  in  the  form  of  eager,  active  emigrants  from  all  parts  of 
Europe, 

Tin-  Bulletin  of  the  Survey  Las  now  reached  the  close  of  the  fourth 
volume,  which  contains  37  articles  and  about  900  octavo  pages.  The 
tenth  annual  report  embraces  550  closely  printed  pages,  octavo,  with  80 
pint cs,  maps,  sections,  &c.  About  50  of  the  plates  illustrate  the  remark- 
;ihh'  cliff-dwellings  which  were  found  by  the  members  of  the  Survey  along 
tin-  canons  of  the  streams  of  Southern  Colorado  and  New  Mexico. 
Volume  IV,  quarto,  on  the  Miocene  and  Pliocene  vertebrates  of  the 
\\Vst,  by  E.  D.  Cope,  and  Volume  XII,  by  Dr.  Joseph  Leidy,  on  the 
IMii/opods,  are  far  advanced,  and  will  be  ready  for  distribution  in  the 
spring,  The  eleventh  annual  report  is  in  press ;  about  300  pages  already 
in  type.  This  volume  will  be  issued  early  in  the  spring. 

Tlic  members  of  the  Survey  are  now  all  in  the  office  from  their  field- 
work,  and  busily  engaged  in  elaborating  their  field-notes.    The  materials 
for4he  twelfth  annual  are  very  ample  and  of  great  interest. 
Very  respectfully,  your  obedient  servant, 

F.  V.  HAYDEN, 

United  States  Geologist. 
Hon.  CARL  SCIIURZ, 

Secretary  of  the  Interior. 


APPENDIX. 


The  following  articles  on  the  geology  of  the  Rocky  Mountain  region  were  published 
in  the  American  Journal  of  Science,  New  Haven,  Conn.,  several  years  ago,  and  are 
now  entirely  out  of  print.  Inasmuch  as  they  contain  some  views  that  have  either 
been  absorbed  or  overlooked  by  modern  geologists,  they  are  reprinted  in  this  connec- 
tion. There  are  some  views  that,  if  written  at  this  time,  might  be  restricted  or  modi- 
fied, but  in  the  main  they  are  correct.  The  articles  are  reprinted  \vithout  any  altera- 
tion. 


SOME  REMARKS  IN  REGARD  TO  THE  PERIOD  OF  ELEVATION  OF 
THOSE  RANGES  OF  THE  ROCKY  MOUNTAINS  NEAR  THE  SOURCES 
OF  THE  MISSOURI  RIVER  AND  ITS  TRIBUTARIES. 


BY  DR.  F.  V.  HAYDENV 


[From  the  American  Journal  of  Science,  vol.  xxxiii,  May.  1862.] 

The  object  of  the  present  article  is  to  showr,  as  nearly  as  can  be  done  from  known 
geological  data,  the  period  of  the  elevation  of  a  portion  of  the  Rocky  Mountains.  My 
observations  have  been  more  especially  confined  to  the  ranges  from  which  the  Missouri 
and  Yellowstone  Rivers,  with  their  numerous  tributaries,  take  their  rise,  though  I  feel 
confident  that  principles  which  will  apply  to  mountains  occupying  so  large  an  area, 
will  also  be  applicable  to  the  whole  Rocky  Mountain  district.  It  will  be  impossible, 
at  this  time,  to  mention  in  detail  all  the  facts  in  support  of  my  statements,  and  there- 
fore I  shall  assume  that  the  reader  has  examined  the  previous  papers  of  my  associate, 
Mr.  Meek,  and  myself.  During  the  coming  year  I  hope  to  prepare  a  series  of  articles 
for  this  journal  which  will  have  a  more  or  less  direct  bearing  on  the  physical  geog- 
raphy of  this  region  and  the  influences  which  gave  to  it  its  present  configuration. 
Some  erroneous  statements,  growing  out  of  our  limited  knowledge  of  the  structure  of 
these  mountain  chains,  may  be  made,  but  these,  when  known,  will  be  corrected. 
(icology  is  a  progressive  science,  and  even  our  best  eiforts  are  but  approximations  to 
truth  rather  than  the  truth  itself. 

The  evidence  seems  tome  to  be  clear  that  the  great  subterranean  forces  that  elevated 
the  western  portion  of  our  continent  were  called  into  operation  toward  the  close  of 
the  Cretaceous  epoch,  and  that  the  gradual  quiet  rising  continued,  without  a  general 
bursting  of  the  earth's  crust,  until  after  the  accumulation  of  the  Tertiary  lignite  de- 
posits, or  at  least  the  greater  part  of  them  ;  also,  that  after  the  fracture  of  the  surface, 
commenced  and  those  great  crust  movements  began  to  display  themselves,  the  whole, 
country  continued  rising,  or  at  least,  though  there  may  have  been  periods  of  subsidence 
or  repose,  there  was  a  general  upward  tendency,  which  has  continued  even  up  to  our 
present  period.  I  hope  hereafter  to  illustrate  the  correctness  of  these  statements  by 
all  the  facts  that  have  been  obtained  in  my  past  explorations  as  well  as  by  those  I  may 
secure  in  the  future. 

Let  us,  in  the  first  place,  examine  some  of  the  barometrical  profiles  across  the  country 
from  the  Mississippi  River  to  the  Pacific  coast,  constructed  under  the  direction  of  the 
War  Department.  Previously,  however,  to  this  examination  we  may  make  the  state- 
ment that  west  of  longitude  98°  the  surface  of  the  country  may  be  separated  into  two 
divisions,  mountain  and  plain,  and  that  a  combination  of  the  two  compose  the  Rocky 

*  For  most  important  information  I  would  direct  attention  to  second  series  of  this 
journal,  articles  xiii,  xxxix,  vol.  iii,  1847,  article  xxxiv,  vol.  xii,  1849,  and  articles  xxiv, 
xxv,  vol.  xxii,  1856,  by  Prof.  J.  D.  Dana,  in  which,  it  seems  to  me,  Avill  be  found  the, 
most  profound,  far-reaching  generalizations  in  regard  to  the  physical  geography  and 
geology  of  the  West  and  other  portions  of  our  country  which  have  ever  been  given  to 
the  public.  The  origin  and  character  of  those  subterranean  forces  which  have  pro- 
duced such  important  results  in  the  West  are  fully  discussed  in  those  papers. 


958     BEPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

M..,mt .'.in  district.  After  leaving  the  Mississippi  the  intervening  country  westward  to 
tin-  upheaved  riders  is  an  apparently  level  or  undulating  plain,  with  no  disturbance 
of  the  strata  of  the  underlying  formations  until  we  come  in  close  proximity  to  some 
of  the  mountain  elevations.  Reaching  the  base  of  the  elevated  ridges  which  form  the 
mountain  crests,  we  at  ouee  commence  a  rugged  and  abrupt  ascent. 

If  we  look  at  the  profile  constructed  by  Governor  Stevens,  from  Saint  Paul,  Minn., 
1-ititude  44°  ">*'  and  longitude  92°  58',  to  the  Pacific  coast,  we  shall  find  that  the  start- 
in^  point  is  s->-'  f.-et  above  the  ocean-level.  Near  Fort  Union,  at  the  junction  of  the 
Wfttcrs  of  the  Yellowstone  and  Missouri,  670  miles  westward,  the  height  above  the 
ocean-level  has  increased  to  2,010  feet,  or  1,182  feet  higher  than  Saint  Paul.  We  thus 
sec  that  the  average  ascent  of  the  country  between  these  two  points  is  not  quite  two 
Vert  to  the  mile.  From  Fort  Union  to  the  valley  of  Dearborn  River,  just  under  the 
base  of  the  elevated  ridges  of  the  principal  eastern  range,  we  find  the  distance  to  be 
44S  miles  and  the  height  above  the  ocean  2,081  feet  greater  then  that  at  Fort  Union, 
or  the  average  rate  (if  ascent  increased  to  nearly  five  feet  per  mile.  Over  this  vast 
extent  of  country  extends  an  almost  limitless  prairie,  apparently  level,  with  no  forests 
or  groves,  with  no  timber  except  that  which  skirts  the  streams.  There  is  in  this  great 
distance  a  gradual  increase  in  the  inclination  of  the  strata  proportioned  to  the  increase 
of  the  ascent,  but  no  marked  disturbance  of  the  beds  until  we  arrive  in  close  proximity 
to  the  mountain  elevations.  There  are  a  few  local  fractures  of  the  earth's  crust  caused 
by  the  elevation  of  the  Bear's  Paw,  Little  Rocky  Mountain,  &c.,  around  which  the  sedi- 
mentary rocks  are  more  or  less  disturbed,  but 'all  these  lesser  mountains  are  more  or 
less  remotely  connected  with  the  main  chain.  After  passing  the  highest  point  of  the 
principal  range,  along  this  line,  which  is  near  Cadotte's  Pass,  we  commence  our  descent 
toward  the  Pacific  very  much  as  we  ascended  the  eastern  slope,  but  over  a  much  more 
rugged  route.  We  find  a  continued  series  of  more  or  less  parallel  ridges  of  elevation 
ninTl  we  approach  the  coast  for  a  distance  of  from  400  to  600  miles.  From  Fort  Walla 
Walla  to  the  ocean,  however,  the  average  descent  is  a  little  less  than  one  foot  to  the 
mile. 

Again,  if  we  e'xamine  the  profile  constructed  by  Fremont,  commencing  at  the  mouth 
of  the  Kansas  River,  we  find  that  the  initial  point  is  690  feet  above  the  ocean.  Pro- 
ceeding westward,  the  average  grade  for  the  first  300  miles  is  between  4  and  5  feet  per 
mile.  Thence  to  Fort  Laramie  the  ascent,  as  stated  by  Fremont,  is  8  feet  to  the  mile, 
and  from  Fort  Laramie  to  Hot  Spring  Gate,  although  still  passing  over  prairie  coun- 
try, tint  average  grade  of  ascent  is  given  by  the  same  explorer  as  45  feet  per  mile. 
Over  this  entire  route,  however,  loaded  wagons  have  been  transported  with  ease: 
When  we  reach  the  foot  of  the  mountains  in  this  direction,  the  lofty  elevated  ridges 
seem  to  rise  abruptly  out  of  the  prairie,  averaging  from  1,000  to  6,000  feet  in  height 
above  the  surrounding  country.  From  thence  to  the  Pacific  coast  we  pass  over  a  con- 
t  i  n  ued  series  of  elevations  which  taken  in  the  aggregate  seem  to  trend  nearly  northwest 
and  southeast,  but  which,  when  examined  in  detail,  often  present  no  definite  direction 
or  continuous  line  of  fracture.  This  mountain  region  is  composed  of  a  series  of  these, 
ridges  forming  a  belt  or  zone  400  to  800  miles  in  width  from  east  to  west,  interspersed 
with  beautiful  valleys  through  which  wind  streams  of  clear  water.  So  numerous  are 
the  profiles  which  have  now  been  made  across  the  continent  by  different  explorers 
that  it  is  hardly  necessary  to  describe  each  one,  since  what  we  have  already  said  in- 
dicates the  object  in  view. 

\\V  have  said  that  the  western  portion  of  our  continent,  especially  if  we  look  only 
;it  the  easterly  slope,  may  very  properly  be  divided  into  mountain  and  prairie.  It  is 
true  that  in  Kansas  and  Iowa,  groves  of  timber  of  considerable  size  are  seen,  but  they 
form  rat  her  the  exception  than  the  rule.  Along  the  eastern  slope  there  is  a  belt  of 
country  :'><><)  to  (500  miles  in  width,  where,  for  the  most  part,  the  only  timber  to  be  seen 
is  a  thin  fringe  bordering  the  streams.  Even  in  the  eastern  portion  of  the  main 
range  the  timber  is  not  luxuriant,  like  that  so  common  along  the  coast  of  Oregon  and 
California.  The  pine  trees  are  seldom  more  than  3  feet  in  diameter. 

A-nin,  we  may  divide  the  mountains  or  elevated  ridges  which  form  the  different 
ranges  into  two  kinds,  viz,  those  with  long  extended  lines  of  fracture,  with  a  granitic 
nucleus  and  a  comparatively  regular  outline,  and  those  which  appear  to  be  composed 


illust  rat  ions  of  t  he  second  class.  From  all  the  information  within  our  reach  we  have 
inferred  that  alter  passing  the  eastern  slope  the  mountain  ranges  of  eruptive  origin 
are  far  the  most  numerous.  We  also  know  from  personal  observation  that  the  main 
range  of  the  Rocky  Mountains  and  the  subordinate  ridges  on  either  side  near  the 
headwaters  of  the  two  principal  branches,  the  Yellowstone  and  Missouri,  are  of  sim- 
ilar Origin  and  present  similar  rugged  features. 
We  may  now  return  to  the  Cretaceous  period.  In  a  previous  paper  in  this  journal,  * 

*Vol.  xxxi,  March,  1861. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       959 

we  remarked  that  there  were  no  indications  in  the  geological  formations  of  that  por- 
tion of  the  West  over  which  we  have  traversed  of  long-continued  deep-water  deposits 
mitil  we  pass  up  into  the  Cretaceous  epoch.  The  lower  portion  of  No.  1,  or  the  Da- 
kota Group,  which  ushered  in  the  Cretaceous  epoch  in  this  portion  of  the  West,  is 
composed  of  coarse  sand,  pebbles,  &c.,  with  ripple  marks,  oblique  laminae,  and  with 
other  indications  of  shallow  water  and  change  of  currents.  The  same  characters  are 
seen  throughout  the  formation  wherever  it  is  exhibited.  We  also  know  from  the  nu- 
merous impressions  of  leaves,  and  some  beds  of  impure  lignite,  that  dry  land  could  not 
have  been  far  distant.  But  as  we  pass  up  through  Nos.  2,  3,  and  4,  whatever  changes 
of  land  may  have  occurred  in  the  mean  time,  we  think  there  were  periods  at  least 
when  the  sea  was  of  considerable  depth  and  suffered  a  quiet  deposition  to  go  on.  We 
infer  this  from  the  fine  and  homogeneous  character  of  the  sediments.  Throughout 
No.  4  we  have  a  fine  plastic  clay  which  continues  up  into  No.  5,  when  a  gradual  change1 
takes  place  from  the  introduction  of  yellowish  ferruginous  matter,  and  a  slow  increase 
of  sandy  sediments.  Toward  the  middle  of  No.  5  the  sand  begins  to  predominate 
until  the  upper  part  becomes  a  coarse  ferruginous  sandstone,  with  all  the  indications 
of  shallow-water  deposits.  We  know,  also,  from  fragments  of  wood  and  impressions 
of  leaves  which  have  been  found  quite  widely  distributed  in  the  upper  part  of  No.  5, 
that  dry  land  could  not  have  been  far  away.  We  also  infer  from  the  character  of  the 
molluscan  remains  that  the  great  Cretaceous  sea  which  had  so  long  spread  its  vast  wa- 
ters over  this  region  was  becoming  shallow,  and  that  a  new  epoch  was  approaching. 
As  we  arise  in  No.  4,  and  pass  up  into  No.  5,  there  is  an  evident  increase  in  the  num- 
ber of  gasteropoda,  indicating  shoal  waters.  We  have  already  remarked  their  peculiar 
Tertiary  aspect,  which  seemed  to  point  directly  to  that  epoch,  showing  that  it  was 
not  far  distant.  We  may  now  ask  the  cause  of  this  apparent  approach  to  land,  as 
foreshadowed  by  the  lithological  as  well  as  the  paleontological  characters  of  the  Up- 
per Cretaceous  formation  No.  5.  We  think  that  the  facts  indicate  that  during  the 
deposition  of  this  formation  the  western  portion  of  the  continent  was  slowly  rising 
above  the  ocean  level,  the  waters  on  the  one  side  receding  toward  the  Pacific,  and  on 
the  other  toward  the  Atlantic,  introducing  the  great  Tertiary  epoch  which  had  already 
been  foretold  in  the  Cretaceous.  At  the  commencement  of  the  Tertiary  period, 
throughout  the  central  portions  of  the  continent,  lakes,  estuaries,  &c.,  more  or  less 
salt,  at  length  becoming  brackish,  and  finally  fresh  water,  existed,  and  a  new  flora 
and  fauna  were  introduced.  The  subterranean  expansive  power  which  was  quietly 
lifting  up  the  country  still  continued,  although  no  bursting  of  the  earth's  crust  had 
commenced.  These  brackish  water-deposits,  which  appear  to  mark  the  dawn  of  the 
Tertiary  period  in  the  West,  are  distributed  quite  widely  over  the  central  portions  of 
the  Rocky  Mountain  district,  and  then,  by  a  general  subsidence  or  a  vast  increase  of 
fresh  water,  the  true  lignite  deposits  spread  themselves  over  large  areas  and  probably 
covered  much  of  the  country  now  occupied  by  the  mountain  ranges,  and  were  doubt- 
less more  or  less  intimately  connected  with  the  Tertiary  beds  on  the  Pacific  coast. 
What  barriers  separated  them  from  the  Tertiary  formations  along  the  Pacific  it  is  im- 
possible from  our  present  limited  knowledge  of  the  geology  of  the  intermediate  region 
to  determine. 

We  have  remarked  that  the  probable  period  of  the  bursting  of  the  earth's  crust 
which  resulted  in  the  formation  of  those  abrupt  mountain  crests  or  ridges,  occurred 
somewhere  near  the  close  of  the  accumulation  of  the  true  lignite  deposits.  We  believe 
this  for  the  following  reasons :  Whenever  we  observe  the  lignite  beds  in  the  vicinity 
of  tin;  mountain  ranges  we  find  them  more  or  less  inclined  in  the  same  direction  with 
the  older  fossiliferous  rocks,  though,  as  a  general  rule,  dipping  at  a  smaller  angle, 
because  more  remote  from  the  axis  of  the  disturbing  power.  Of  course,  as  the  land 
was  slowly  elevated  toward  the  surface  of  the  waters,  the  newer  Tertiary  beds  would 
be  subjected  to  the  erosive  action  of  water  first,  and  thus  continuing  downward,  as 
the  mass  was  slowly  rising,  until  the  granitic  nucleus  was  exposed.  The  Tertiary 
rocks,  being  composed  for  the  most  part  of  loose,  yielding  material,  sands,  clays  and 
lignites,  would  be  worn  away  from  the  surface  for  some  distance  from  the  axis  of  ele- 
vation. Although  the  lignite  Tertiary  beds  are  developed  in  full  force  all  along  the 
base  of  the  larger  ranges  of  mountains,  it  is  not  unlikely  that  some  of  these  ridges 
formed  barriers  or  lofty  shores  to  these  great  Tertiary  lakes.  It  would  seem  as  if  this 
country  during  the  Tertiary  period  was  not  unlike  the  Undine  region  of  the  north,  so 
called  by  the  geographer  Nicollet  on  account  of  the  great  number  of  fresh-water  lakes 
distributed  over  that  district. 

Near  the  Black  Hills  these  beds  are  worn  away  from  the  immediate  base  of  the 
mountains,  and  it  is  doubtful  from  any  proofs  that  we  can  now  obtain  whether  the  Ter- 
tiary lake  extended  over  the  country  at  that  time  occupied  by  the  Black  Hills.  West 
of  this  range,  the  lignite  Tertiary  beds  incline  from  the  western  slope  5  to  10  degrees. 
All  along  the  Bighorn  Mountains,  the  same  features,  only  more  strongly  marked,  are 
seen.  These  beds  often  lie  quite  high  upon  the  slopes  of  the  mountains,  conforming  to 
the  Cretaceous  rocks  and  sometimes  inclining  at  a  high  angle.  Between  the  western 
extremity  of  the  Bighorn  Range  and  the  Sweet  Water  Mountains  on  the  North  Plat  to 


£)60  REPORT    OF    THE    SECRETARY    OF    THE    INTERIOR. 

Thev  are  more  disturbed  than  sit  any  other  locality.  The  lignite  Tertiary  strata  are 
nearlv  vertical  and  the  hard  layers  of  sandstone  or  limestone  extend  in  long  project- 
inirlh.rsjirn.ssih.'  ro.n.try,  while  the  intermediate  yielding  beds  of  clay,  sand  and 
li-nite  an-  sinootl.rd  and  leveled  by  atmospheric  agencies  and  clothed  with  a  thick 
turf  of  "rass.  Ml  along  the  Larainie  Range,  from  the  Red  Buttes  to  Deer  Creek,  until 
tin-  lignite  l>rds  air  concealed  by  the  White  River  Group,  the  same  features  are  seen, 
though  the  strata  incline  less,  being  more  remote  from  the  anticlinal  crest.  On  both 
rides  of  the  Wind  River  .Mountains  the  same  phenomena  occur,  and  other  examples 
init'ht  br  ritrd  pointingto  the  same  conclusions,  but  enough  has  been  said  to  show  that 
it  is  probable  that  the  lignite  Tertiary  beds  partook  of  the  same  movements  that  have 
elevated  ihr  older  fossiliferous  rocks.  We  therefore  infer  that  the  fracture  of  the 
earth's  crust  in  (his  portion  of  the  West,  by  Avhich  the  nucleus  of  the  mountains  was 
revealed,  oceurred  near  the  time  of  the  accumulation  of  the  lignite  deposits  or  at  the 
close  <>t' that  epoch. 

Again,  although  there  is  not  a  strict  iinconforniability  between  the  true  lignite  beds 
andlhe  Wind  River  Group,  the  latter  incline  in  the  same  direction,  only  at  a  much 
smaller  angle.  Near  the  source  of  Wind  River  the  Wind  River  Group  rests  directly 
npon  Cretaceous  formation  No.  2.  At  this  point  the  Cretaceous  rocks  incline  from  10° 
to  -J.V,  while  the  Wind  River  beds  dip  from  1°  to  5°.  As  we  ascend  the  valley  of 
Wind  River  towards  its  source,  we  pass,  for  a  long  distance,  the  steeply  inclined  Cre- 
taceous and  Jurassic  rocks,  along  the  margins  of  the  mountains  on  our  left  hand, 
while  on  our  right,  but  a  few  hundred  yards  distant,  the  naked,  almost  vertical  walls 
of  the  lower  portion  of  the  Wind  River  Group*  are  seen,  the  strata,  however,  seldom 
inclining  more  than  one  degree. 

The  same  examples  may  be  observed  on  the  west  side  of  the  Wind  River  Mountains, 
where  the  Wind  River  beds  lie  high  upon  the  sides  of  the  w ester n  slope  in  a  very 
slightly  inclined  position  and  in  some  localities  covering  the  very  summit,  showing 
clearly  that  even  the  dividing  crest  of  the  mountains  was  beneath  the  waters  during 
the  deposition  of  this  group.  Along  the  margins  of  both  the  Wind  River  and  the  Big- 
horn Mountains  these  beds  seem  to  have  risen  in  an  undisturbed  or  in  a  nearly  horizonta  1 
condition.  We  have  already  expressed  the  opinion  in  a  previous  paper, t  that  the 
Wind  River  Group  was  intermediate  in  age  between  the  lignite  Tertiary  and  the  White 
River  l>eds,  and  in  point  of  time  filled  up  a  chronological  chasm.  WTe  have  inferred 
this  from  t  lie  fact  that  these  beds  seem  to  possess  paleontological  and  lithological 
characters  intermediate  between  the  two.  They  contain  casts  of  a  species  of  Vivipam 
•which  is  undistinguishable  from  V.  trocliiformis,  and  fragments  of  a  Trionyx  apparently 
the  same  with  that  occurring  in  the  lignite  beds,  also  fragments  of  a  Testndo  which, 
so  far  as  we  can  determine,  is  identical  with  the  T.  Xebrascensis  of  the  White  River 
beds.  If  we  look  also  at  the  composition  of  the  Wind  River  beds,  we  find  that  their 
light  color,  indurated  arenaceous  and  argillaceous  character,  and  their  general  appear- 
ance after  erosion,  favor  the  correctness  of  the  inference  in  regard  to  their  interme- 
diate position.  From  the  facts  before  us  in  regard  to  this  group,  we  conclude  that 
even  after  the  crust  broke,  the  country  continued  slowly  rising  while  the  Wind  River 
deposits  were  accumulating,  and  that  the  upper  portions  when  not  eroded  away  were 
elevated  high  upon  the  sides  of  the  mountains  in  a  nearly  horizontal  position. 

Again,  the  White  River  beds  hold  a  similar  position  with  reference  to  the  lignite 
formations  as  the  Wind  River  Group.  They  are  seldom  disturbed,  and  only  in  a  few 
instances  do  they  incline  as  much  as  5°.  They,  however,  occur  high  up  on  the  mount- 
ain slopes  along  both  sides  of  the  Laramie  Range,  showing  that  they  partook  of  the 
gradual  elevation  of  the  country,  after  the  crust  was  broken  and  the  mountain  district 
began  to  approach  its  present  configuration.  On  the  west  side  of  the  Black  Hills, 
where  t  he  White  River  beds  probably  began  their  origin,  we  find  only  the  lower  strata 
of  this  group,  usually  reposing  directly  upon  Cretaceous  rocks,  though  in  a  few  locali- 
ties upon  lignite  formations.  But  as  we  descend  south  and  southwestward,  these 
lower  beds  disappear  and  more  recent  ones  take  their  place,  until  they  pass  into  the 
Pliocene  sands  of  the  Loup  River  Group,  and  then,  in  turn,  still  farther  southward, 
an-  lost  in  the  Loess  or  yellow  marl  deposits.  We  can  only  account  for  these  phenom- 
ena on  the  supposition  that  this  great  Tertiary  fresh-water  lake  had  its  commence- 
ment in  the  White  River  Valley,  and  as  the  Black  Hills,  and  of  course  the  whole  Rocky 
Mountain  district,  arose  slowly  toward  its  present  elevation,  the  waters  gradually  re- 
ceded southward  and  sonthwestward,  and  then  more  recent  beds  continued  to  be  ac- 
cumulated, until  this  formation  spread  itself  over  the  vast  area  which  it  now  occu- 
pies. We  thus  think  that,  by  means  of  these  Cretaceous  and  Tertiary  deposits  of  the 
\\cNt.  weean  yet  trace  step  by  step  the  progress  of  that  grand  development  which 
has  given  the  present  geographical  conformation  to  the  West,  and  originated  the 
fountains  from  which  flow  those  mighty  rivers  which  may  well  be  called  the  commer- 
cial arteries  of  the  American  continent. 

Another  illustration  of  the,  gradual  and  long-continued  rise  of  the  country  niav  be 
tonnd  in  the  immense  chasms  or  canons  which  have  been  formed  by  the  streams  along 

"  Same  as  the  Wahsatch  Group,  1878. 

t  ISee  this  Journal,  vol.  xxxi,  March,  1861. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       961 

the  mountain  sides.  We  can  only  account  for  them  on  the  supposition  that  as  the  an- 
ticlinal crest  was  slowly  emerging  from  the  sea,  the  myriad  sources  of  our  great  rivers 
were  seeking  their  natural  channels,  and  that  these  branches  or  tributaries  began  this 
erosive  action  long  before  the  great  thoroughfares,  the  valleys  of  the  Mississippi  and 
the  Missouri,  were  marked  out.  The  erosion  would  go  on  as  the  mountains  continued 
slowly  rising  at  an  almost  imperceptible  rate,  and  in  process  of  time  the  stupendous 
channels  which  everywhere  meet  us  along  the  immediate  sides  of  the  mountains  would 
be  formed.  If  we  examine  the  barometrical  profiles,  already  referred  to,  we  see  at  a 
glance  that  in  traversing  the  country  from  the  Mississippi  to  the  foot  of  the  mount- 
ains the  ascent  is  very  gradual,  but  increases  as  we  approach  the  upheaved  ridges.  In 
an  equal  proportion  will  the  rapidity  and  consequently  the  erosive  power  of  the  streams 
be  increased  so  that  we  may  readily  account  for  those  grand  displays  of  the  erosive 
action  of  water  which  occur  so  frequently  along  the  mountain  sides.  Eastward  from 
the  mountains,  beyond  this  immediate  influence,  the  descent  is  so  gradual  that  the 
Missouri  flows  quietly  along  over  its  yielding  alluvial  bed,  transporting  its  sediments 
to  the  Gulf  of  Mexico. 

That  the  progressive  elevation  of  the  country  continued  up  to  our  present  period,  or 
•at  least  until  near  the  time  of  the  deposition  of  the  most  recent  superficial  deposits, 
we  think  we  have  evidence  derived  from  the  terraces,  which  are  seen  all  along  the 
streams.  The  elevation  of  these  terraces  increases  as  we  approach  the  sources  of  the 
rivers,  averaging  from  a  few  feet  to  150  or  200  feet  in  height.  This  subject  will  be  dis- 
cussed more  fully  in  a  future  article. 

We  conclude,  therefore,  that  the  barometrical  profiles,  constructed  from  explora- 
tions across  our  continent,  and  geological  data,  indicate  a  long-continued  quiet  expan- 
sion of  the  earth's  crust,  commencing  toward  the  close  of  the  Cretaceous  epoch  and 
extending  even  to  our  present  period ;  that  near  the  close  of  the  accumulation  of  the 
Tertiary  lignite  deposits,  the  crust  of  the  earth  had  reached  its  utmost  tension,  the 
long  lines  of  fractures  had  commenced,  and  the  anticlinal  crests  of  the  mountain 
ranges  were  marked  out.  In  a  previous  paper  in  this  Journal,  we  remarked  that  there 
is  no  unconformability  in  any  of  the  fossiliferous  sedimentary  strata  in  the  Northwest, 
from  the  Potsdam  sandstone  to  the  summits  of  the  true  lignite  Tertiary.  We  believe, 
therefore,  that  the  elevated  ridges  which  form  the  nuclei  of  the  mountain  ranges 
began  to  emerge  above  the  surface  of  the  surrounding  country  near  the  close  of  the 
Eocene  period.  We  think  also  that  the  evidence  is  clear  that  there  were  periods  of 
subsidence  and  repose ;  but  the  thought  which  we  wish  to  illustrate  is,  that  there  was 
a  slow,  long-continued,  quiet,  upward  tendency  which  began  near  the  close  of  the  Cre- 
taceous epoch  and  culminated  in  the  present  configuration  of  the  western  portion  of 
our  continent  near  the  commencement  of  our  present  period. 
WASHINGTON,  D.  C.,  January  1,  1862. 


ART.    XXXIV. -REMARKS    ON    THE    GEOLOGICAL    FORMATIONS 
ALONG  THE  EASTERN  MARGINS  OF  THE  ROCKY  MOUNTAINS.* 


BY  F.  V.  HAYDEN. 


[From  the  American  Journal  of  Science,  May,  1868.] 

On  several  former  occasions  I  have  described  the  different  geological  periods  repre- 
sented by  the  rocks  uplifted  along  the  margins  of  the  Rocky  Mountains  and  especially 
along  the  eastern  slope.  Examinations  over  a  great  extent  of  country  in  considerable 
detail,  from  latitude  49°  south  nearly  to  the  Arkansas  River,  have  shown  me  that 
quite  marked  lithological  and  paleontological  changes  occur  in  them  all  as  we  proceed 
from  the  north  southward.  It  is  the  purpose  of  this  article  to  note  this  fact  some- 
what more  in  detail  than  hitherto.  Beginning  with  the  nucleus  of  the  Rocky  Mount- 
ains at  any  point  along  the  eastern  range,  we  find  it  composed  of  massive  granite 
rocks,  mostly  red  feldspathic,  but  not  unfrequently  gray  or  other  shades  of  color ;  then 
a  series  of  metamorphic  rocks  (as  they  are  usually  called,  though  no  doubt  all  the 
granites  should  be  included  with  them),  syenites,  diorites,  clay,  mica,  and  hornblende 
slates,  and  igneous  rocks  of  various  kinds  here  and  there. 

Proceeding  outward,  we  find  the  Silurian  period  represented  by  the  Potsdam  sand- 
stone ,  Devonian  wanting,  then  Carboniferous,  Red  Beds  (Triassic  ?),  Jurassic,  Creta- 

*  This  article  refers  only  to  the  eastern  ranges  of  the  Rocky  Mountains,  extending 
south  to  the  Arkansas.     The  same  remarks  may  or  may  not  apply  to  other  portions. 
61 1 


962     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

ceons,  and  Tertiary,  all  connected  together  in  the  regular  order  of  sequence,  and  all 
l.nt  I!M-  most  recent  Tertiary  in  strict  conformity.  The  Tertiary  deposits  do  not  ex- 
liil.it  :mv  marked  change  either  in  their  mineral  or  fossil  contents  from  the  northern 
i.ori ion  of  our  domain  to  the  Arkansas,  but  the  Cretaceous  beds  present  several  quite 
marked  rliaii"rs.  N«»s.*  .">  and  4  maintain  their  peculiar  characters  as  shown  on  the 
I'jmcr  Missouri,  wherever  they  are  exposed  all  along  the  eastern  slope,  except  that 
tli.-y  contain  comparatively  few  fossils,  yet  a  few  characteristic  species  are  found 
win-revel-  these  beds  are  seen,  which  identify  them.  On  the  Missouri  River,  No.  3  at- 
tains M  -Teat  thickness,  400  to  600  feet,  presenting  massive  escarpments  of  yellow 
chalk  and  it  can  hi;  traced  all  the  way  across  the  prairie  country  lying  between  98° 
and  KID-  lon"ii  ude.  At  Forts  Hayes  and  Wallace  on  the  Union  Pacific  Railway,  East- 
ern Division,  there  are  massive  beds  of  this  chalk  which  is  sawed  into  building  blocks 
with  a  common  saw,  and  in  many  instances  it  is  nearly  as  white  as  our  chalk  of  com- 
merce and  might  be  used  for  the  same  purposes. 

The  two  characteristic  species  of  fossils  of  this  division  are  found  everywhere, 
Osti-ea  congesta  and  Inoceramus  problematic^.  All  along  the  slope  of  the  mountains 
No.  3  still  retains  its  chalky  nature,  but  becomes  quite  shaly,  none  of  the  layers 
ever  becoming  more  than  oiie  or  two  inches  in  thickness.  This  is  the  case  at  the' 
sources  of  the  Missouri  along  the  Bighorn  and  Wind  River  Mountains  also,  from  the 
South  Pass  to  Pike's  Peak,  and  on  the  western  slope  wherever  this  bed  is  exposed. 
Near  Denver,  at  Marshall's  coal-mine,  No.  3  has  been  changed  by  heat  into  a  grayish 
mm  pact  limestone,  quite  hard  and  brittle  in  its  fracture,  which  makes  an  excellent 
flux  in  smelting  ores.  But  this  change  is  local,  for  16  miles  north  of  this  point  it  pre- 
sents the  same  laminated  character.  It  seems  that  No.  3  loses  its  massive  chalky 
character,  by  which  it  first  attracted  attention  on  the  Missouri  River,  in  its  westward 
extension,  so  that  along  the  margins  of  the  mountains,  except  in  one  locality,  it  can- 
not prove  of  any  economical  value,  while  between  98°  and  100°  longitude  it  becomes 
very  useful  not  only  for  lime,  but  also  for  building  purposes.  No.  2,  like  Nos.  4  and  5, 
retains  its  dark  plastic  clay  character  everywhere  that  it  has  been  observed,  but,  like 
the  others,  it  is  not  nearly  as  well  developed  in  Colorado  as  on  the  Upper  Missouri. 
Near  Fort  Benton  it  attains  a  thickness  of  200  to  400  feet,  while  in  Colorado  it  is  not 
more  than  50  to  150  feet.  Between  longitude  96°  and  99°  No.  1  retains  its  deep  rust- 
red  sandy  characters  with  dicotyledonous  leaves  from  the  Missouri  River  to  the  Ar- 
ka nsus,  but  nowhere  along  the  margins  of  the  mountains  from  latitude  49°  to  Pike's 
Peak  have  I  ever  seen  any  well-defined  palseontological  proof  of  its  existence.  Near 
Fort  Benton  are  a  series  of  Cretaceous  beds  containing  some  seams  of  impure  lignite 
and  numerous  species  of  fossils,  not  one  of  which  is  identical  with  those  so  abundant 
in  Nos.  4  and  5  lower  down  on  the  Missouri.  'These  beds  have  been  placed  provision- 
ally in  the  general  section  as  a  portion  of  No.  1,  but  the  region  about  Fort  Beuton 
needs  a  more  careful  examination  before  any  positive  conclusions  can  be  arrived  at. 
Around  the  Black  Hills  is  a  bed  of  massive  siliceous  rocks,  some  layers  forming  a  pud- 
ding stone,  which  in  some  localities  takes  the  name  of  fortification  rocks.  These  hold 
a  position  between  No.  2  Cretaceous  and  the  Jurassic  marls.  The  same  are  seen  along 
the  margin  of  the  Bighorn  Mountains,  in  which  I  observed  a  bed  of  impure  lignite,  an 
abundance  of  silicified  wood,  and  some  uncharacteristic  Saurian  bones.  From  the 
Wind  River  Mountains  to  Pike's  Peak  these  same  siliceous  and  pebble  cemented  rocks 
occur  holding  the  same  geological  position, -forming,  as  it  were,  beds  of  transition  be- 
tween the  Cretaceous  and  the  Jurassic  periods.  I  have  carefully  examined  these  rocks 
for  hundreds  of  miles  and  have  never  yet  detected  any  organic  remains,  animal  or 
vegetable,  in  them. 

The  Jurassic  beds,  as  revealed  along  the  mountains,  possess  peculiar  and  marked 
lithological  characters,  so  that  having  identified  them  by  the  fossils  in  one  locality  we 
•can  trace  them  over  great  areas.  They  were  first  shown  to  exist  in  the  West  in  the 
form  of  a  zone  engirdling  the  Black  Hills.  They  here  attain  a  thickness  from  200  to 

)0  feet  at  least,  and  from  the  beds  in  this  locality  alone  have  fossils  enough  been  col- 
lected of  such  unmistakable  Jurassic  types  as  to  prove  their  existence  beyond  a  doubt. 
But  these  beds  have  also  been  shown,  since  they  were  first  made  known  in  the  Black 
Hills,  to  l)e  exposed  along  the  margins  of  the  Bighorn  and  Wind  River  Mountains 
near  Red  Buttes,  on  North  Platte,  and  in  numerous  localities  in  the  Laramie  Plains, 
and  west  ward  to  Fort  Bridger.  So  numerous  are  the  species  now  known  from  the  West 
and  so  close  are  the  affinities  of  most  of  them  to  well-known  Jurassic  tvpes  that  it 
is  not  necessary  for  me  in  this  place  to  detail  the  evidence  in  support  of  that  state- 
ment. 

It  is  sufficient  to  remark  that  the  Jurassic  system  is  quite  plainly  represented  along' 
the  mar-ins  of  the  different  ranges  of  mountains  north  of  latitude  42°.  but  proceeding 
southward  from  Deer  Creek  on  the  North  Platte,  the  Jurassic  beds  diminish  in  force 
tear  Cache  la  Poudre  it  becomes  doubtful  whether  they  are  represented  at  all' 

*  The  different  divisions  of  the  Cretaceous  period,  as  shown  on  the  Missouri  River, 
have  received  geographical  names,  as  Fort  Benton  Group,  &c.,  but  I  use  the  old  divis- 
ions by  figures  for  brevity. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       963 

At  tliis  point  there  is  a  thin  bed,  perhaps  20  to  50  feet  in  thickness,  of  greenish-gray 
arenaceous  marl  overlying  the  Red  Beds,  which  seem  to  occupy  the  place  of  the  Juras- 
sic. This  seems  to  thin  out  more  and  more  as  we  proceed  southward  toward  the  Ar- 
kansas. From  Deer  Creek  100  miles  north  of  Fort  Laramie  to  Denver,  a  distance  of 
400  miles,  I  have  searched  in  vain  for  any  organic  remains  in  the  rocks  which  appear 
to  represent  the  Jurassic  period  of  the  Black  Hills,  Bighorn  and  Wind  River  Moun- 
tains. In  the  Red  Beds  or  supposed  Triassic  no  organic  remains  have  been  found  north 
of  the  Arkansas,  and  they  do  not  differ  much  lithologically  in  their  southward  exten- 
sion, except  that  they  seem  to  be  much  thicker  and  more,  gypsiferous  northward.  In 
the  far  north  the  Carboniferous  rocks  are  in  many  localities  500  to  1,500  feet  in  thick- 
ness, and  even  as  far  south  as  the  Red  Buttes  the  massive  beds  of  limestone,  with  true 
Carboniferous  fossils,  are  exposed  500  to  1,000  feet  thick,  and  are  quite  distinct  from 
the  red  or  variegated  beds.  But  as  we  proceed  southward  from  this  point  the  Carbon- 
iferous limestones  seem  to  lose  their  usual  lithological  characters  and  the  Red  Beds 
prevail.  At  the  head  of  Pole  Creek  on  the  eastern  margin  and  in  the  Laramie  Plains 
west,  the  Carboniferous  rocks  are  mostly  of  a  red  arenaceous  character,  with  a  few  lay- 
ers 2  to  10  feet  in  thickness  of  whitish  or  yellowish  limestone.  From  these  limestones 
I  collected  Productus  Prattenianus,  Atliyris  suMUta,  and  other  well-known  Carbonifer- 
ous forms. 

Above  these  Red  Beds,  which  contain  intercalated  layers  of  limestone,  is  a  considerable 
thickness  of  purely  red  arenaceous  beds,  but  in  studying  all  these  rocks  with  some 
care  from  Pole  Creek  nearly  to  Pike's  Peak,  I  could  not  separate  the  Red  Beds  from  the 
Carboniferous  by  any  break  in  continuity,  and  I  was  rather  inclined  to  the  opinion 
that  inasmuch  as  a  large  portion  of  the  gypsiferous  or  variegated  beds  could  be  shown 
to  be  Carboniferous,  they  might  possibly  all  be  included  in  that  period.  TLe  Potsdam 
sandstone,  the  only  portion  of  the  Silurian  era  ever  detected  along  the  eastern  slope 
of  the  Rocky  Mountains  north  of  the  Arkansas,  seems  to  fade  out  entirely  south  of  the 
Red  Buttes  on  the  North  Platte.  It  is  well  denned  around  the  Black  Hills,  Bighorn, 
and  Wind  River  Mountains.  Near  the  Red  Buttes  there  is  a  bed  of  siliceous  pudding 
stone  resting  on  the  metamorphic  rocks  which  may  be  the  Potsdam  in  its  southern 
extension,  but  south  of  Fort  Laramie  to  Pike's  Peak  it  is  somewhat  doubtful  whether 
any  trace  of  it  exists.  If  it  occurs  at  all  it  a  very  thin  layer,  for  the  most  part  con- 
cealed. So  far  as  I  could  determine,  the  Carboniferous  rocks  rest  directly  (though  not 
conforming)  upon  the  metamorphic  rocks.  There  is  also  some  change  in  the  nuclei 
of  the  mountain  ranges  southward.  At  the  north  the  feldspathic  and  the  gray  gran- 
ites prevail,  but  southward  the  syenites  and  igneous  rocks  form  the  central  portions 
of  the  mountains  almost  entirely.  It  is  rare  to  see  true  granite. 

The  above  remarks,  founded,  on  observations  that  have  been  made  over  a  very  great 
extent  of  country  through  a  period  of  many  years,  lead  me  to  the  following  conclu- 
sions : 

1st.  That  all  the  formations  of  the  West  undergo  more  or  less  change  both  in  their 
mineral  and  fossil  contents  in  their  extension  toward  the  west  and  south.  They  all 
seem  to  reach^  their  culmination  not  far  from  the  central  portion  of  the  great  area 
drained  by  the  Missouri,  and  lose  to  a  great  extent  their  distinctive  characters  beyond 
its  limits. 

2d.  The  Potsdam  sandstone  and  the  Jurassic  beds  present  more  remarkable  changes 
than  any  of  the  others.  While  north  both  these  formations  are  well  marked,  both 
lithologically  and  paloeontologically  in  their  southward  extension  they  gradually  fade 
out,  so  that  south  of  Fort  Laramie  to  Pike's  Peak  it  becomes  a  matter  of  doubt  whether 
they  exist  at  all.  The  inference  therefore  is  that  these  groups  of  rocks  are  not  well 
defined,  if  they  occur  at  all  south  of  the  Arkansas.  In  support  of  this  statement  is  the 
fact  that  although  this  southern  region  has  been  traversed  in  every  direction  by  mul- 
titudes of  explorers  for  thirty  years  past,  among  whom  have  been  geologists  of  high 
reputation,  yet  south  of  latitude  40°  not  a  single  animal  fo.ssil  has  ever 'been  detected 
with  Jurassic  affinities,  and  it  is  quite  doubtful  whether  any  have  been  found  with 
Triassic  or  Permian  relations;*  even  the  few  plants  that  have  been  found  are  doubtful 
in  their  affinities  and  are  regarded  as  probably  Cretaceous  or  Permian.  I  have  made 
these  remarks  from  the  fact  that  all  the  observations  that  have  been  made  by  explorers 
in  the  West  during  the  past  will,  ere  many  years,  be  put  to  the  rigid  test  of  a  most 
careful  scrutiny,  and  an  error  by  whomsoever  made,  though  sustained  by  the  highest 
authority  in  the  land,  will  fall  to  the  ground  before  the  light  of  true  science  as  the 
dead  bark  from  a  tree.  The  ease  with  which  the  Rocky  Mountain  region  can  soon 
be  reached,  in  a  few  years,  when  our  great  national  highways  are  completed  to  the  Pa- 
cific, will  induce  the  best  geologists  in  this  country  and  in  Europe  to  visit  them,  and 
the  many  intricate  problems  of  Rocky  Mountain  geology  must  be  solved. 

*  I  do  not  wish  to  be  understood  as  saying  that  the  Jurassic  rocks  do  not  occur,  south 
of  the  Arkansas,  as  well  as  the  Permian  and  Triassic,  for  there  is  ample  room  for  their 
fullest  development,  but  no  evidence  has  ever  yet  been  obtained  of  its  (Jurassic)  exist- 
ence, although  the  country  has  been  so  long  traversed  by  explorers.  The  evidence,  so 
far  as  it  goes,  would  seem  to  be  against  its  occurrence  at  all. 


964     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

Tho  school  of  mines  which  will  no  doubt  be  soon  established  in  the  heart  of 

thl  mhn  is  Its  of  the  Rocky  Mountains,  must  gather  around  it  able  men  who 
will  1'IZ^us.Mh'  onvj.ct  the  observations  of  other  investigators  who  have  exam- 
iiinl  tlu-  coiiniry  under  less  favorable  auspices. 


THE  PRIMORDIAL  SANDSTONE  OF  THE  ROCKY  MOUNTAINS  IN  THE 
NORTHWESTERN  TERRITORIES  ON  THE  UNITED  STATES. 


BY  DR.  F.  V.  HAYDEN. 


[From  the  American  Journal  of  Science  and  Arts,  vol.  xxxiii,  Jan.,  1862.] 

We  have  attempted  in  this  paper  to  present  as  clear  and  connected  an  account  as 
the  known  facts  will  permit,  of  the  Primordial  rocks  west  of  the  Mississippi,  more 
especially  those  of  the  northwest,  west  of  longitude  96°.  The  Potsdam  sandstone  of 
the  New  York  series  is  the  division  of  the  Primordial  zone  of  Barrande,  mainly  repre- 
sented in  the  Rocky  Mountain  district,  and  is  that  part  alluded  to  unless  otherwise 
mentioned. 

In  speaking  of  the  geographical  distribution  of  the  Potsdam  sandstone  reterence 
will  lie  made  to  localities  to  the  eastward  where  it  has  furnished  most  abundant  and 
sat  isf'actory  testimony  in  regard  to  its  age.  We  will,  in  the  first  place,  present  more 
in  detail  such  facts  as  Ave  have  been  able  to  obtain  by  personal  observation  in  the 
field,  and  by  the  aid  of  these  and  the  statements  of  reliable  explorers  we  hope  to  give 
some  idea  of  the  geographical  extension  of  this  wide-spread  formation  in  the  West. 

Our  first  knowledge  of  Primordial  rocks  west  of  the  Missouri  River  was  obtained 
in  the  summer  of  1857,  during  the  exploration  of  the  Black  Hills  of  Nebraska,  by  an 
expedition  under  the  command  of  Lieut.  G.  K.  Warren,  Topographical  Engineers.  The 
more  important  facts,  with  the  determination  of  the  fossils,  were  published  by  Mr. 
Meek  and  the  writer  in  March,  1858.* 

By  reference  to  the  general  map  of  the  country  west  of  the  Mississippi,  recentlv 
published  under  the  auspices  of  the  War  Department,  we  find  that  the  Black  Hills  lie 
between  the  43d  and  45th  degrees  of  latitude,  and  the  103d  and  104th  degrees  of  longi- 
tude, and  occupy  an  area  about  80  miles  in  length,  and  from  30  to  50  in  width.  Ac- 
cording to  Lieutenant  Warren  the  shape  of  the  mass  is  elliptical  and  the  major  axis 
trends  about  20°  west  of  north.  The  base  of  these  hills  is  about  2,500  to  3,000  feet,  and 
the  highest  peaks  6,700  feet  above  the  ocean.  The  entire  range  is  clasped,  as  it  were, 
by  the  North  and  South  Branches  of  the  Shyenne  River,  the  most  inportaut  stream  in 
this  region.  The  North  Branch  passes  along  the  north  side  of  the  range,  receiving 
most  of  its  waters  from  it,  but  taking  its  rise  far  to  the  westward  near  the  sources  of 
Powder  River,  in  the  "divide,"  between  the  waters  of  the  Yellowstone  and  those  of 
the  Missouri.  The  South  Branch  also  rises  in  the  same  "  divide,"  flows  along  the  south- 
ern base  of  this  range,  receiving  the  waters  of  numerous  tributaries  which  have  their 
sources  in  it. 

Again,  by  referring  to  the  map  above  alluded  to,  we  ascertain  that  the  Black  Hills 
form  the  most  eastern  outlier  of  the  great  Rocky  Mountain  Range  as  well  as  the  first 
point  where  rocks  older  than  the  Carboniferous  are  exposed  to  the  eye  after  leaving  the 
Missouri  westward.  These  hills  would  seein  to  constitute  an  independent  elevation, 
so  far  are  they  removed  from  other  ranges,  were  it  not  for  a  low  anticlinal  which  may 
be  traced  across  the  plain  country  southward,  connecting  them  with  the  Laramie 
Mountains  near  Laramie  Peak.  The  central  portion  is  composed  of  red  feldspathic 
granite  and  stratified  Azoic  rocks,  and  resting  unconformably  upon,  and  forming  a 
zone  or  belt  around  the  ellipsoidal  nucleus,  are  a  series  of  variable,  reddish  ferrugi- 
nciiis  sandstones,  which  by  their  organic  remains  furnish  the  most  reliable  evidence 
that  tlu-y  belong  to  the  Potsdam  period. 

As  observed  in  and  around  the  Black  Hills,  the  Potsdam  sandstone  presents  a  great 
varn-t  v  of  lithological  characters.  In  many  localities  it  is  composed  of  a  conglomer- 
ate of  more  or  less  water-worn  pebbles,  mostly  whitish  crystalline  quartz,  but  repre- 
senting to  a  greater  or  less  extent  the  different  varieties  of  the  changed  rocks  beneath. 
Tin-  pelililrs  vary  in  wize  from  an  eighth  of  an  inch  to  four  inches  in  diameter  cemented 
toi;rtln  r  with  a  si  li  co-calcareous  paste.  Some  of  the  pebbles  are  scarcely  worn  while 
•  •t  1  HTM  are  quite  smooth.  At  the  locality  where  the  following  section  was  taken,  the 
sandstone  is  of  a  gray  color  tinged  with  red  at  the  base,  but  ascending  it  becomes  more 

*  Proceedings  of  the  Academy  Nat.  Sci.,  Pa.,  March,  1858. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       965 

ferruginous  until  its  color  is  a  dark  dull  red,  and  its  texture  a  coarse-grained  friable 
sandstone  with  many  quartzose  and  micaceous  particles  and  some  calcareous  matter. 
Seams  two  to  four  inches  in  thickness  are  very  nearly  composed  of  shells  of  the  gen- 
era Lingula,  Obolella,  &c.,  which,  though  quite  fragile  in  their  nature,  are  so  well 
preserved  as  to  be  easily  identified.  The  following  section  taken  near  the  central  por- 
tion of  the  Black  Hills  exhibits  Carboniferous  rocks  and  the  Potsdam  sandstone  con- 
forming to  each  other,  but  the  latter  resting  discordantly  upon  the  Azoic  stratified 
and  granitic  rocks. 

Feet. 

1.  A  hard,  compact,  fine-grained  yellowish  limestone  of  an  excellent  quality, 
passing  down  into  a  yellow  calcareous  sandstone,  quite  friable.    Fossils:  Spi- 
rifer  fiockymontana,  Marcou;  an  Athyris,  like  A.  subtilita,  Cyploceras,  &c 50 

2.  Loose  layers  of  very  hard  yellow  arenaceous  limestone  with  a  reddish  tinge, 
underlaid  by  a  bed,  six  to  eight  feet  in  thickness,  of  very  hard  blue  limestone  ; 
the  whole  contains  great  quantities  of  broken  crinoidal  remains  with  cya- 
thophylloid  corals  and  several  species  of  brachiopoda 40 

3.  Variegated  sandstone,  of  a  gray  and  ferruginous  red  color,  composed  chiefly 
of  grains  of  quartz  and  particles  of  mica  cemented  with  calcareous  matter. 
Some  portions  of  the  bed  are  very  hard,  compact,  siliceous ;  others  a  coarse 
friable  grit;  others  a  conglomerate.     Fossils  :  Lingula pj-ima,  L.  antiqua,  Obo- 
lella nana,  and  fragments  of  a  trilobite,  Arionellus  f  Oweni 50  to  80 

4.  Stratified  Azoic  rocks  standing  in  a  vertical  position  for  the  most  part. 

Leaving  the  Black  Hills  in  a  direction  a  little  west  of  south,  we  follow  an  anticlinal 
valley  to  the  Laramie  Mountains  with  which  the  Black  Hills  seem  thus  obscurely  con- 
nected. The  evidence,  so  far  as  it  goes,  appears  to  indicate  that  the  same  force  which 
elevated  the  one  raised  the  other,  and  that  the  events  were  synchronous.  We  do  not 
observe  the  lower  rocks  after  leaving  the  Black  Hills  until  we  reach  the  source  of  the 
Niobrara  River,  where  we  find  a  series  of  horizontal  strata  resting  upon  the  vertical 
edges  of  Azoic  clay  slates  and  schists,  which  from  their  lithological  characters  and 
position  doubtless  belong  to  the  age  of  the  Potsdam  sandstone,  though  no  organic 
remains  could  be  found.  The  following  section  shows  the  descending  order  of  the 
beds. 

Feet. 

1.  Quartzose  sandstone,  some  parts  filled  with  pebbles 22 

2.  Red  argillaceous  slate  1 5 

3.  Sandstone,  dull  reddish  ferruginous,  like  bed  1,  above 37 

4.  A  series  of  strata  more  or  less  inclined,  composed  of  gneiss  with  silvery  rnica 
in  large  plates,  micaceous  and  talcose  slates,  white  quartz,  &c. 

We  have  no  doubt  that  the  Potsdam  sandstone  occurs  in  the  form  of  an  outcropping 
belt  all  along  the  Laramie  range  of  mountains,  though,  after  a  thorough  search  we 
were  unable  to  discover  any  organic  remains.  Having  once  fixed  the  position  and 
age  of  a  formation,  as  the  Potsdam  sandstone  is  established  in  the  Black  Hills,  we 
may  rely  with  considerable  confidence  upon  the  physical  characters  and  stratigraph- 
ical  position  to  determine  the  age  of  rocks  in  the  same  district  of  country.  We  have 
on  these  grounds  regarded  certain  rocks  along  the  Laramie  Range  as  of  this  age.  In 
the  first  ridge  of  elevation  west  of  the  trading  post  on  La  Prele  Creek,  about  60  miles 
northwest  of  Fort  Laramie,  is  a  series  of  rocky  layers  50  feet  in  thickness,  reposing 
unconformably  upon  red  feldspathic  granites,  mica  schists,  and  clay  slates.  The  lower 
portion  is  a  fine-grained  subcrystalliiie  quarfczose  rock,  partially  metamorphosed,  pass- 
ing up  into  a  friable  sandstone  arranged  in  thin  layers,  with  the  laminae  quite  oblique, 
overlaid  by  a  considerable  thickness  of  conglomerate.  The  dip  is  about  20°  east.  Rest- 
ing upon  these  supposed  Potsdam  rocks  at  this  point  and  inclining  at  about  the  same 
angle  are  layers  of  limestone,  containing  numerous  fossils  which  prove  them  to  belong 
to  the  Carboniferous  age. 

Again,  further  southward  along  the  same  range,  near  the  source  of  the  Chugwater 
River  we  find  the  same  limestones  well  developed,  containing  some  Carboniferous 
fossils,  and  underneath  them  and  inclining  in  the  same  direction  is  a  group  of  strata 
of  a  brick-red  color,  more  or  less  changed  by  heat,  holding  the  position  of  the  Pots- 
dam sandstone  in  other  localities.  In  some  places  these  rocks  are  so  metamorphosed 
by  heat  from  beneath  as  to  appear  like  a  red  feldspathic  granite,  and  in  others,  like 
a  reddened  granular  sandstone  containing  numerous  unchanged  masses  of  quartz. 

At  the  Shyeime  Pass,  we  observed  the  well-known  Carboniferous  rocks,  inclining 
about  13°.  Beneath  them  is  a  considerable  thickness  of  red  marls  and  laminated 
sandstone,  and  still  farther  down  and  inclining  26°  is  a  quartzose  sandstone,  full  of 
water-worn  pebbles,  passing  down  into  layers  which  at  a  distance  look  like  indurated 
clay,  but  which,  011  closer  examination,  proved  to  be  an  aggregation  of  quartz  and 
feldspar  crystals  cemented  with  a  calcareous  paste.  At  another  locality  we  have  the 
following  characters :  (1)  a  grayish  quartzose  sandstone,  12  inches;  then  descending, 
(2)  laminated  granitoid  rock,  2  feet;  (3)  compact  reddish  ferruginous  granitoid  mate- 


966     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

rial,  8  feet ;  (4)  a  considerable  thickness,  perhaps  50  feet,  of  feldspar  crystals  cemented, 
with  a  calcareous  paste,  inclining  13°.  Though  we  could  find  no  organic  remains  in 
thes.e  supposed  Potsdam  rocks  along  the  Laramie  range  of  mountains,  yet  their  strati- 
graphical  position  and  physical  characters  leave  very  little  room  for  doubt  as  to  their 
age. 

Although  we  think  that  the  known  facts  justify  the  inference  that  the  Potsdam 
sandstone  is  revealed  in  an  outcropping  belt  all  along  the  margins  of  the  Bighorn 
Range,  resting  uncoiiformably  upon  the  Azoic  rocks  beneath,  yet  we  were  unable  to 
make  a  careful  examination  except  in.  a  few  localities.  We  could  see,  however,  in 
the  loose  material  scattered  along  the  foot  of  the  mountains,  washed  down  by  the 
streams,  masses  of  sandstone  closely  resembling. the  rock  under  consideration.  Near 
the  source  of  Powder  River  we  penetrated  to  the  nucleus  of  the  mountains  and  found 
a  series  of  sandstones  underlying  the  Carboniferous  limestone  and  resting  uuconform- 
ably  upon  the  schistose  and  clay  slates  of  the  Azoic  series,  in  very  nearly  the  same 
manner  as  in  the  Black  Hills  before  described..  The  Potsdam  sandstone  in  this  region 
is  quite  well  developed,  attaining  a  thickness  of  200  feet,  and  exhibiting  its  usual 
variable  lithological  characters.  Near  the  base,  the  rock  is  of  a  reddish  flesh-color, 
very  compact,  composed  of  an  aggregation  of  quartz  pebbles,  varying  in  size  from  a 
minute  grain  of  quartz  to  masses  half  an  inch  in  diameter,  cemented  with  siliceous 
matter.  Portions  of  the  rock  contain  many  pebbles  of  jasper  which  appear  to  have 
been  slightly  worn  before  being  inclosed  in  the  calcareous  paste.  Passing  up  we  find 
the  rock  to  be  arranged  in  thin  ferruginous  layers,  slightly  calcareous  but  mostly 
siliceous,  with  many  small  particles  of  mica.  These  thin  layers  are  also  charged  with 
fossils,  as  Lingula  antiqua,  Obolella  nana,  Theca  greyarea,  and  Arionellus  f  OwenL  Many 
of  the  slabs  were  covered  with  fucoidal  markings  and  what  appear  to  be  tracks  or 
trails  of  worms.  The  upper  part  of  'this  formation  as  seen  in  the  Bighorn  Mountains 
is  a  rust-color  granular  sandstone,  the  small  siliceous  grains  being  held  together  by  a 
calcareous  cement  which  causes  the  rock  to  effervesce  briskly  on  the  application  of  an 
acid.  In  tracing  the  different  fossiliferous  rocks,  at  this  locality,  from  the  nucleus 
outward,  we  can  see  a  good  illustration  of  the  strict  conformability  of  all  the  forma- 
tions from  the  Potsdam  sandstone  to  the  summit  of  the  Lignite  Tertiary.  We  see  here 
the  evidences  of  only  two  great  periods  of  disturbance,  the  one  occurring  prior  to  the 
deposition  of  the  Primordial  sandstones  which  inclined  the  Azoic  rocks,  and  the  other 
at  the  close  of  the  accumulation  of  the  true  Lignite  Tertiary  deposits  when  the  mount- 
ain nuclei  began  their  elevation  above  the  surrounding  country. 

Along  the  Wind  River  Mountains,  which  extend  far  northward  and  form  the  dividing 
crest  of  the  great  Rocky  Range,  the  Potsdam  sandstone  is  quite  thinly  represented  and 
yielded  no  organic  remains  to  a  somewhat  hasty  examination.  Near  the  junction  of 
the  three  forks  of  the  Missouri,  alternate  strata  of  clay,  limestone,  and  compact  sili- 
ceous rock  occur  beneath  well-marked  Carboniferous  beds.  These  rocks  are  evidently 
of  ancient  date,  and  were  deposited  in  quite  shallow  water,  as  is  shown  by  numerous 
thin  layers  of  rock  covered  with  trails  of  worms  and  fucoidal  plants.  These  facts 
thus  enumerated  would  seem  to  indicate  with  considerable  certainty  that  this  rock 
once  spread  over  the  area  occupied  by  the  central  range  of  the  Rocky  Mountains, 
doubtless  extending  far  north  beyond  the  limits  of  the  territories  of  the  United  States. 
The  predominance  of  eruptive  rocks  as  we  pass  northward  along  the  main  range  of 
the  Rocky  Mountains  greatly  increases  the  difficulty  in  tracing  out  the  lower  fossili- 
ferous beds. 

We  have  now  described  this  member  of  the  Primordial  zone  as  far  as  it  has  occurred 
within  the  limits  of  our  own  observations.  It  now  becomes  an  interesting  point  to 
determine  its  geographical  extension  in  the  West,  and  for  that  purpose  we  propose  to 
summon  all  the  evidence  at  our  command.  The  proof  will  not,  however,  be  as  satis- 
factory as  could  be  desired,  owing  to  the  general  absence  of  organic  remains. 

If  we  now  extend  our  examinations  far  north  into  the  Hudson's  Bay  territory,  we  find 
that  much  interesting  information  has  been  obtained  in  regard  to  the  Silurian  rocks  of 
that  region,  but  not  accompanied  by  the  evidence  which  gives  to  the  knowledge  ac- 
quired that  definiteness  which  is  desirable.  It  is  probable,  however,  that  when  not 
eroded  away  or  concealed  by  more  recent  deposits,  the  Potsdam  sandstone  and,  per- 
haps, rocks  of  more  recent  Silurian  age  occur  all  along  the  margins  of  the  Rocky 
Mountains  to  the  Arctic  Sea.  To  what  extent  still  more  recent  or  Upper  Silurian  occur 
over  this  vast  region  our  present  knowledge  will  not  enable  us  to  determine,  but  the 
few  fossils  which  have  been  collected  indicate  that  the  great  Silurian  Sea  extended  over 
much  of  the  Northwest.  Sir  John  Richardson  mentions  the  existence  of  conglomerates 
and  sandstones  to  which  succeed  limestones  and  clay  slates,  probably  of  Silurian  age, 
and  granite.  We  know  that  in  many  localities  in  the  mountains,  about  the  sources  of 
the  Missouri,  the  rocks  of  the  Potsdam  period  are  composed  of  sandstones  and  more  or 
less  coarse  conglomerates.  Underneath  are  clay  slates  and  very  hard  limestones  of 
Azoic  age,  and  to  these  succeed  granite.  As  we  proceed  northward  the  evidence  'of 
true  Lower  Silurian  rocks  gives  place  to  those  of  Upper  Silurian  age,  which  have  fur- 
nished a  good  supply  of  organic  remains.  According  to  Mr.  Isbister,  these  rocks  are 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       967 

well  developed  around  Hudson's  Bay,  Great  Slave  Lake  and  River,  Lake  Winnipeg, 
&c.  He  cites  numerous  fossils  as  belonging  to  Silurian  types,  but  the  species  are  too 
numerous  to  mention  here.  We  may  simply  state  that,  so  far  as  our  knowledge  extends, 
there  is  no  evidence  which  renders  it  certain  that  any  portion  of  the  Primordial  zone  of 
of  Barande  occurs  north  of  latitude  49°,  though  it  is  quite  probable  that  when  care- 
fully sought  after  it  will  be  found  revealed  along  the  margins  of  the  mountain  eleva- 
tions to  the  Arctic  Sea. 

As  we  proceed  southward  along  the  line  of  the  mountain  ranges  toward  New  Mexico, 
though  no  fossils  have  been  found,  we  feel  safe,  acting  upon  our  previous  knowledge, 
in  regarding  the  evidence  as  quite  clear  that  this  sandstone  occurs  in  numerous  local- 
ities. In  our  investigations  of  the  geology  of  the  West,  we  have  relied  on  three  tests 
of  evidence,  viz : 

First.  Paheontological  evidence,  which  is  the  most  important  and  in  most  instances 
the  only  conclusive  proof. 

Second.  Stratigraphical  position. 

Third.  Lithological  resemblance. 

The  last  two  tests  are  all  we  have  to  rely  upon  to  determine  the  extension  of  the 
Lower  Silurian  rocks  as  we  proceed  southward  from  the  Black  Hills.  Having  traced 
rocks  which  we  regard  of  this  age  south  to  a  point  on  a  parallel  with  the  Salt  Lake 
district,  we  present  the  following  resemblances  in  Iithol6gical  characters  as  probable 
evidence  of  their  existence  in  Utah  Territory : 

Professor  Hall,  in  Stansbury's  report,  in  several  places  describes  a  bed  of  sandstone 
corresponding  in  its  lithological  characters  and  geological  position  to  the  Potsdam 
sandstone  in  the  Black  Hills.  Stansbury  Island  (Great  Salt  Lake),  the  summit  of  which 
is  3,000  feet  in  height,  is  capped  with  Carboniferous  limestones,  which  rest  upon  a 
coarse  sandstone  or  conglomerate.  Again,  north  of  Great  Salt  Lake  City  the  limestone 
overlies  a  coarse  sandstone  or  conglomerate,  which  almost  invariably  accompanies  it* 
In  several  localities,  as  at  Promontory  Point  and  near  Mud  Island,  the  metamorphic 
strata  appear  to  be  overlaid  by  a  coarse  conglomerate  or  coarse  sandstone,  which  is 
partially  altered  and  assumes  the  character  of  a  quartz  rock.  Marcou,  in  the  [third 
volume  of  Pacific  Railroad  reports,  page  156,  mentions  a  formation  occurring  near  the 
Aztec  Mountains.  He  says:  "We  traveled  seven  miles  upon  the  granite,  then  a  bed 
of  red  sandstone  ;  above  this  the  beds  of  limestone  and  gray  sandstone  belonging  to  the 
mountain  limestone."  The  following  day  "  we  traveled  three  miles  on  the  granite,  the  re- 
mainder on  the  Old  Red  Sandstone."  An  excellent  diagram,  illustrating  a  section  of  the 
rocks  near  the  mountains  above  alluded  to,  accompanies  Mr.  Maroon's  remarks,  which 
would  apply  equally  well  to  similar  beds  in  the  Black  Hills.  The  great  uniformity  in 
the  physical  characters  of  the  different  formations  over  large  areas,  which  have  been 
examined  with  care  and  definite  knowledge  obtained,  leads  us  to  place  some  degree  of 
confidence  in  the  above  statements.  From  latitude  49°  to  40°  south,  and  east  of  the 
dividing  crest,  we  have  the  Potsdam  sandstone,  then,  immediately  above  it,  with  re- 
markable uniformity,  a  series  of  beds  of  limestones  containing  true  Carboniferous  fos- 
sils. We  infer,  therefore,  that  both  northward  and  southward  the  same  uniformity  of 
geological  structure  continued,  unless  we  have  evidence  to  the  contrary. 

The  observations  of  Dr.  J.  S.  Newberry  render  it  quite  probable  that  rocks  of  Lower 
Silurian  age  occur  along  the  valley  of  the  Colorado.  The  following  paragraphs  from 
a  letter  addressed  to  the  writer  by  Dr.  Newberry  are  extracted  by  permission  : 

"I  have  never  collected  any  unmistakable  Silurian  fossils  in^the  far  West, 
perfectly  satisfied  that  the  lower  stratified  rocks  of  the  Colorado  section  are  Silurian, 
but  the  only  fossils  they  contain  are  too  much  changed  to  be  satisfactorily  identified. 

"  The  lower  rocks  above  the  granite  are  coarse,  red  sandstones,  lithologically  and 
stratigraphically  corresponding  to  your  Potsdam  of  the  Black  Hills;  above  these  a 
great  thickness,'  over  300  feet,  of  shales,  limestones,  and  sandstones,  and  then  the  first 
Carboniferous  fossils. 

"Just  above  the  Potsdam  (?)  is  a  limestone  filled  with  corals,  apparently  Ckatoto 
lycoperdon,  or  rather  the  same  with  that  so  common  in  the  Trenton,  with    DTftE 
stems,  formerly  included  in  C.  lycoperdon,  but  evidently  distinct,     On  the  mount:. ins 
bounding  the  Colorado  basin  the  Carboniferous  rocks  rest  directly  upon  the  granite. 

We  have  now  considered  the  Potsdam  sandstone  in  its  geographical  extension  over 
the  West  as  far  as  we  are  acquainted  with  its  existence,  and  have  pointed  out  the  lo- 
calities where  it  is  revealed.     Along  the  Mississippi  Valley  and  eastward  most    in 
portant  discoveries  are  made  annually,  which  show  it  to  be  developed  ev<-rywli« 
when  the  conditions  are  favorable  for  its  exhibition.     It  is  true  that  m  some  looalit 
beds  of  more  recent  age  repose  directly  upon  Azoic  rocks,  but  m  those  rases  IM:;Y  not 
the  Primordial  sandstones  lie  concealed  or  be  eroded  away!     Die  researches  ol  Dr.  i». 
F.  Shumard  in  Texas  have  shown  that  the  Primordial  zone  attains  aconsideraW 
thickness  in  the  Southwest,  and  is  charged  with  an  interesting  group     I   its  peculiar 
fossil  forms.     The  examination  of  others  proved  its  existence  all  along  ilu- 
coast  extending  westward  from  Canada  to  Wisconsin,  Iowa,  ami  Mmn-sota. 
a  great  period  in  the  world's  geological  history,  formerly  supposed  to  possess  b 


968     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

meager  fauna,  the  first  representatives  of  life  on  our  globe,  has  already  yielded  very 
abundant  and  varied  forms.  The  following  is  a  summary  of  the  principal  facts  and 
conclusions  from  our  knowledge  of  the  Potsdam  sandstone  in  the  far  West : 

1.  We  have  the  most  undoubted  evidence  of  the  existence  of  that  division  of  the 
Primordial  zone,  which  is  the  equivalent  of  the  Potsdam  sandstone  of  the  New  York 
series  in  two  important  ranges  of  mountains,  outliers  of  the  great  Rocky  Mountain 
chain.     All  the  fossils  are  well  known  Primordial  types,  and  at  least  two  species  are 
identical  with  forms  occurring  at  the  typical  localities  of  this  period  in  the  Eastern 
States.     The  others  are  forms  closely  allied  to  species  found  in  the  equivalent  rocks 
both  in  this  country  and  in  Europe. 

2.  This  division  of  the  Primordial  zone,  as  a  rule,  appears  as  an  underlying  forma- 
tion, when  the  conditions  are  such  as  to  expose  it  to  view,  from  the  Atlantic  coast  to 
the  crest  of  the  Rocky  Mountains,  and  probably  farther.     Localities  doubtless  do  occur 
where  rocks  of  more  recent  age  than  the  Potsdam  sandstone  rest  directly  upon  the 
Azoic  or  granitic  rocks  below ;  but  these  facts  to  not  militate  against  the  general  rule. 
Having  proved  its  existence  in  two  important  ranges  of  mountains  from,  its  organic 
remains,  by  means  of  lithological  resemblance  and  stratigraphical  position,  we  have 
with  considerable  confidence  traced  it  by  personal  observations  throughout  the  mount- 
ainous district  comprised  within  latitude  40°  and  49°  and  longitude  103°  and  112°.    From 
these  facts  and  the  observations  of  reliable  explorers  in  different  parts  of  the  West,  we 
we  think  we  are  warranted  in  the  belief  that  this  rock  is  exposed  all  along  the  margins  of 
the  Rocky  Mountain  Range  when  not  eroded  away  or  concealed  by  overlying  formations. 
How  far  westward  of  the  dividing  crest  of  the  Rocky  Mountains  it  extended  we  have  no 
data  for  determining,  nor  can  we  hope  to  have,  where  eruptive  rocks  seem  to  predomi- 
nate.    As  yet  we  have  not  known  the  Potsdam  sandstone  to  be  exposed,  except  along 
mountains  with  a  true  granite  nucleus. 

3.  Wherever  this  rock  occurs,  we  are  struck  not  only  with  the  peculiarity  of  the 
organic  remains,  but  also  with  the  remarkable  uniformity  in  the  nature  of  the  sedi- 
ments and  the  general  lithological  appearance,  compared  with  its  equivalents  in  more 
eastern  localities.    We  do  not  believe  this  to  be  due  to  currents  of  water  bearing  the 
materials  from  far  eastern  lands,  but  that  the  sediments  were  obtained  from  the  vicinity, 
and  that  the  uniformity  in  their  character  arises  from  the  nature  of  the  underlying 
rocks  from  which  they  were  derived. 

The  Potsdam  sandstone  is  everywhere  composed  of  calcareous  and  silicious  matter, 
granular  quartz,  ferruginous  material  in  great  quantities,  also  pebbles  of  various  kinds 
worn  and  unworn,  with  now  and  then  seams  and  layers  of  argillaceous  material.  We  find 
in  the  Azoic  rocks  below  an  abundance  of  limestone,  clay  slates,  mica  schists,  seams  of 
white  quartz,  granite  composed  largely  of  feldspar,  and  we  can  readily  detect  the  source 
of  the  fragmentary  masses  which  form  the  conglomerates.  We  also  know  that  while 
nuclei  of  certain  mountain  ranges  on  the  eastern  slope  are  composed  of  a  massive 
feldspathic  granite,  a  great  thickness  of  more  recent  or  overlying  rock,  forming  the 
lower  and  smaller  ridges,  are  composed  of  a  kind  of  "rotten  granite,"  which  is  so  full  of 
the  hydrated  oxide  of  iron  that  it  readily  decomposes  on  exposure  to  the  atmosphere. 
We  therefore  believe  that  the  source  of  all  the  sediments  composing  the  Primordial 
rocks  in  the  West  can  be  traced  to  the  underlying  rocks  in  the  vicinity. 

4.  There  are  no  indications  of  long-continued  deep  water  in  the  Primordial  sea,  so 
far  as  the  West  is  concerned.     If  we  examine  the  lower  part  of  the  Potsdam  sandstone, 
we  find  that  the  physical  conditions  which  ushered  in  this  period  were  quite  violent, 
as  is  shown  by  the  conglomerate  character  of  the  rock.    Passing  upward,  this  conglome- 
rate graduates  into  a  rock  composed  of  granules  of  quartz  and  small  plates  of  mica 
cemented  with  calcareous  matter,  and  about  midway  in  the  formation  we  have  a  fine, 
very  ferruginous  calcareous  sandstone,  in  thin  layers,  filled  with  fossils  in  a  very  good 
state  of  preservation.     The  condition  of  the  organic  remains,  the  fineness  of  the  sedi- 
ment, and  the  perfect  horizontality  of  the  laminae  of  deposition  indicate  a  short  period 
at  least  of  quiet  water.     As  we  continue  upward  the  rocks  begin  to  show  the  shifting 
nature  of  the  currents,  shallow  water  and  perhaps  a  proximity  to  land,  by  oblique 
laminae  of  deposit,  ripple  markings,  and  fucoidal  remains.     The  upper  portion  of  this 
rock  contains  no  fossils,  nor  wrere  the  physical  conditions  such  as  to  have  preserved 
them  even  if  they  had  existed. 

5.  There  seem  to  be  evidences  of  a  gradual  thnining  out  of  the  Primordial  sandstone 
in  its  far  western  extension,  as  also  of  all  the  Palaeozoic  formations.     According  to 
Dr.  Owen,  the  Protozoic  sandstones  in  Minnesota  are  at  least  500  to  600  feet  in  thick- 
ness, and  in  Iowa  Professor  Whitney  estimates  them  at  from  250  to  400  feet.     In  Ten- 
nessee Professor  Saiford  finds  several  thousand  feet  of  rocks,  which  he  refers  to  this 
age ;  and  in  Texas,  where  they  seem  to  be  quite  well  exhibited  and  to  yield  a  large 
number  of  fossils,  Dr.  Shumard  gives  them  as  only  about  500  feet.     In  the  Rocky 
Mountain  district  they  are  seldom  more  than  80  feet  and  never  over  200  feet.     Indeed, 
all  the  Primary  fossiliferous  rocks  are  but  thinly  represented  there,  while  the  lower 
Secondary  formations  begin  gradually  to  increase  in  force  until  all  along  the  eastern 


GEOLOGICAL    SURVEY    OF    THE    TERRITORIES.  969 

slope  we  have  an  enormous  development  of  the  Upper  Secondary  and  Tertiary,  with  an 
aggregate  thickness  of  from  8,000  to  10,000  feet. 

6.  So  far  as  we  yet  know,  there  is  no  unconformability  in  any  of  the  fossiliferous 
sedimentary  rocks  of  the  Northwest  from  the  Potsdam  sandstone  to  the  summit  s  <»r  i  In- 
true  Lignite  Tertiary.     There  are  proofs  of  two  great  periods  of  disturbance  which 
had  a  marked  influence  upon  the  physical  geography  of  the  West.     The  one  occurred 
prior  to  the  deposition  of  the  Potsdam  sandstone,  when  the  Azoic  or  granitic  rocks 
were  elevated  into  a  more  or  less  inclined  position,  and  the  other  and  most  important 
period  took  place  at  the  close  of  the  accumulation  of  the  great  Lignite  Tertiary  de- 
posits, when  the  great  lines  of  fracture  were  produced  and  the  massive  nuclei  of  the 
mountain  ranges  wefe  raised  above  the  surrounding  country. 

7.  What  changes  took  place  in  the  physical  geography  of  the  West  during  the  long 
period  which  must  have  elapsed  after  the  deposition  of  the  Potsdam  sandstone  until 
the  commencement  of  the  Carboniferous  age,  we  have  very  few  data  to  determine. 
We  are  inclined  to  think  that  this  portion  of  the  West  at  least  was  elevated  above  the 
water  level  during  the  greater  part  of  that  period  ;  the  numerous  indications  of  shal- 
low water  during  the  accumulation  of  the  Potsdam  sandstone  and  the  almost  entire 
absence  of  rocks  of  intermediate  age  over  so  large  an  area  further  strengthens  that 
opinion.     It  is  true  that  in  the  far  Northwest  we  have  proofs  that  the  hiatus  is  partially 
filled,  but  in  the  South  and  Southwest  the  evidence  is  still  more  meager.    Near  the 
Humboldt  Mountains,  in  Utah,  Messrs.  Meek  and  Engelmann  have  detected  proofs  of 
Devonian  rocks,  but  they  are  not  known  to  be  largely  developed,  and  on  the  western 
declivity  of  the  El  Paso  Mountains  Dr.  G.  Shuniard  found  "well-marked  strata  of  the 
inferior  Silurian  system  corresponding  in  age  to  the  Blue  Limestone  of  Cincinnati  and 
the  Hudson  River  Group  of  the  New  York  series."*     But  so  far  as  our  present  knowl- 
edge extends,  rocks  of  intermediate  ages  do  not  form  a  prominent  feature  in  the 
geology  of  the  West. 

WASHINGTON,  November,  1861. 


SKETCH  OF  THE  GEOLOGY  OF  THE  COUNTRY  ABOUT  THE  HEAD- 
WATERS OF  THE  MISSOURI  AND  YELLOWSTONE  RIVERS 


By  Dr.  F.  V.  HAYDEN. 


[From  the  American  Journal  of  Science  and  Arts,  vol.  xxxi,  March,  1861.] 

The  observations  made  during  the  recent  expedition  to  the  headwaters  of  the  Mis- 
souri and  Yellowstone  Rivers,  under  the  command  of  Capt,  William  F.  Rayuolds,  To- 
poo-raphical  Engineers,  have  served  to  extend  quite  largely  our  knowledge  of  the  geo- 
graphical area  of  the  different  geological  formations  already  indicated  as  existing  m 
the  far  West.     I  propose  in  the  following  paper  to  present  a  brief  abstract  ot  the  Lead- 
ing facts  ascertained  with  a  view  to  their  bearing  upon  the  physical  geology  of  the 
mountain  chains.     I  know  that  it  will  be  impossible  within  the  limits  of  a  single  paper 
to  make  every  point  as  clear  as  could  be  desired,  or  to  use  terms  in  all  cases  in  thru- 
usually  restricted  sense.     Much  of  the  country  passed  over,  west  ot  thy  1 
had  never  before  been  explored  by  scientific  men,  no  maps  existed  NY!...  ln-\ 
topoo-raphy  with  any  pretensions  to  accuracy,  and  the  mount;..  n  ran^s  xvh.rh  wen 
known  to  e^ist  in  that  region  from  information  given  by  traders  and  ,,,„  ,,,,,  -s  w,-,v  ,„ 
always  laid  down  in  thei?true  geographical  localities  or  with  their  pio,,,     . 
not  until  the  forthcoming  report  of  Captain  Raynolds  now  iiy-ours,-  ,.l   ,,1,-,  . 
appears  can  these  deficients  be  supplied.     Moreover,  the  wild  an.    hro  k,-    ,•  ,.    . 
of  the  surface  of  the  country  examined,  uninhabited  «^&""bg  '  ' 
Indians,  precluded  the  possibility  of  perfect  accuracy  in  all  Hu'.nn  no    d  t 
can  only  hope  that  we  have  obtained  a  general  idea  ot  tin-  l>nnr.  „  1  , 
tures  of  the  vast  area  explored.     The  rocks  observed  belong  to  the  clil. 
periods  in  the  following  order  : 

I.  Granite,  stratified  Azoic,  and  eruptive  rocks.T 


-Transactions  of  the  Academy  of  Sciences,  Saint  Louis, 

,is  BsS*»St?»«aa 


......  '  .......  "• 


tion,  at  various  periods. 


970     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

II.  Potsdam  sandstone  (Silurian). 

III.  Carboniferous  rocks  (including  Permian?). 

IV.  Red  arenaceous  deposits. 
V.  Jurassic  beds. 

VI.  Cretaceous,  with  its  divisions. 
VII.  Tertiary  deposits. 

I. — GRANITE,  STRATIFIED  AZOIC,  AXD   ERUPTIVE   ROCKS. 

Under  the  first  division  of  my  subject  I  will  take  up  the  mountain  elevations  as  they 
appeared  in  their-  detached  portions  along  our  route.  It  is  now  well  known  that  the 
term  "Rocky  Mountains"  is  quite  general  in  its  application,  including  a  vast  number 
of  more  or  less  important  ranges  of  mountains,  which,  when  examined  in  detail,  seem 
to  have  been  elevated  with  very  little  regularity  and  in  many  instances  to  be  but 
slightly  connected,  but  when  viewed  in  the  aggregate  to  present  a  trend  nearly  north- 
west and  southeast.  Before  reaching  the  main  range  we  find  along  the  eastern  slope 
many  detached  minor  elevations  showing  the  wide  geographical  area  under  which  the 
elevating  forces  acted. 

I  allude  in  the  first  place  to  the  Black  Hills,  the  northern  portion  of  which  we  ex- 
amined on  our  route  from  Fort  Pierre,  on  the  Missouri,  to  the  Yellowstone  River.  These 
hills  form  the  most  eastern  outlier  of  the  Rocky  Mountains,  and  would  seem  to  be  an 
independent  elevation  were  it  not  for  a  low  anticlinal  which  extends  across  the  plain 
country  southward,  connecting  it  with  the  Laramie  Mountains.  The  central  portion  is 
composed  of  a  coarse  flesh-colored  feldspathic  granite,  with  a  series  of  metainorphic 
slates  and  schists  superimposed,  and  thence,  upon  each  side  of  the  axis  of  elevation, 
the  various  fossiliferous  formations  of  this  region  follow  in  their  order  to  the  summits 
of  the  Cretaceous,  the  whole  being  more  or  less  inclined  against  the  granitic  rocks. 
The  distance  across  the  granitoid  nucleus  is  from  15  to  30  miles,  and  on  each  side  of 
the  crest  or  axis  of  elevation  we  find  the  corresponding  portions  of  the  fossiliferous 
beds  from  the  Silurian  to  the  summit  of  the  Cretaceous.  The  evidence  therefore  is 
conclusive  that  all  the  unchanged  sedimentary  strata  at  a  period  of  comparatively 
recent  date  extended  continuously  over  the  whole  area  occupied  by  the  Black  Hills. 
The  eruptive  rocks  reveal  themselves  at  various  localities,  as  at  Bear  Peak,  Inyankara 
Peak,  &c.  Bear  Peak  is  a  protrusion  of  very  compact  igneous  rocks,  almost  isolated 
from  the  main  range  of  the  Black  Hills,  and  Inyankara  Peak  is  for  the  most  part 
composed  of  pentagonal  basaltic  columns  arranged  in  a  vertical  position.  There  is  no 
evidence,  however,  that  they  were  formed  by  any  force  independent  of  that  which 
elevated  the  entire  range  of  mountains. 

The  next  range  that  we  examined  was  the  Big  Horn,  which  is  perhaps  the  most  im- 
portant detached  outlier  on  the  eastern  side  of  the  main  crest  of  the  continent.  This 
seems  to  trend  nearly  northwest  and  southeast,  extending  into  the  valley  of  the  Yel- 
lowstone. The  nucleus  of  these  mountains  is  also  composed  of  red  feldspathic  granite, 
with  a  series  of  stratified  Azoic  rocks ;  and  the  unchanged  sedimentary  strata  to  the 
summit  of  the  Cretaceous  and  including  a  portion  of  the  Lignite  Tertiary  can  be  seen 
in  regular  sequence  outward  inclining  at  greater  or  less  angles.  From  the  observations 
of  Dr.  C.  M.  Hines,  who  acted  -as  geologist  to  the  exploring  division  under  Lieutenant 
Maynadier,  we  know  that  the  corresponding  formations  occur  on  the  opposite  side  of 
the  axis  of  elevation,  and,  as  we  remarked  of  the  Black  Hills,  we  may  infer  from  this 
fact  that  the  unchanged  sedimentary  beds  once  extended  continuously  over  the  whole 
area  occupied  by  the  Big  Horn  Mountains,  in  a  nearly  horizontal  position,  some  time 
during  the  Tertiary  period.  As  we  pass  along  the  northeastern  base  of  the  Big  Horn 
Mountains  southwestward,  the  ridges  of  upheaval  seem  to  be  presented  en  echelon,  the 
range  gradually  making  a  flexure  around  to  the  westward.  Toward  the  headwaters 
of  Wind  River  this  range,  as  it  attaches  itself  to  the  main  chain  of  the  mountains, 
changes  its  lithological  characters,  no  true  ancient  granitic  rocks  being  seen,  but  in- 
stead, lofty  peaks  composed  of  eruptive  rocks,  presenting  every  variety  of  structure, 
from  compact  basalt  to  porous  lava-like  masses. 

The  Laramie  Mountains,  by  which  we  mean  the  whole  range  from  the  Red  Buttes  to 
the  Arkansas,  were  examined  with  some  care*  from  Red  Buttes  southward  nearly  to 
Pike's  Peak.  There  is  a  remarkable  similarity  in  the  general  geological  features  of 
all  the  mountains  on  the  eastern  slope.  The  more  lofty  elevations,  as  Long's  and  Pike's 
Peaks,  with  other  ridges  and  peaks  scarcely  less  lofty  than  those  just  mentioned,  are 
composed  of  the  same  coarse  feldspathic  granite  before  alluded  to,  but  the  lower  ridges 
are  formed  to  a  great  extent  of  a  ferruginous  feldspathic  granite  which  easily  yields 
to  atmospheric  agencies,  and  the  surface  of  the  country  is  paved  with  crystals  of  feld- 
spar in  consequence  of  its  decomposition.  All  along"  the  base,  and  often  extending  up 
to  the  crest  of  the  mountains,  we  see  the  outcropping  edges  of  the  fossiliferous  rocks 
inclining  at  greater  or  less  angles,  and  on  crossing  over  into  the  Laramie  Plains  we 
find  the  corresponding  strata  leaning  from  the  opposite  side.  The  granitoid  nucleus 
varies  from  8  to  20  miles  in  width.  No  indications  of  true  eruptive  rocks  were  observed 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       971 

in  tliis  range.  The  Medicine  Bow  and  Sweet  Water  Mountains  appear  to  be  of  the 
same  character  for  the  most  part,  but  011  the  east  side  of  the  Sweet  Water  River  the 
evidence  of  igneons  action  is  shown  on  a  large  scale.  The  ancient  volcanic  material 
would  seem  to  have  been  elevated  to  a  great  height  in  but  a  partially  fluid  condition 
and  then  to  have  gradually  cooled,  affecting  to  a  greater  or  less  extent  the  fossilifer- 
ous  strata  in  contact. 

Near  the  junction  of  the  Popo  Agie  with  Wind  River  we  came  in  full  view  of  the 
Wind  River  Mountains,  which  form  the  dividing  crest  of  the  continent,  the  streams  on 
the  one  side  flowing  into  the  Atlantic  and  those  on  the  other  into  the  Pacific.  This 
range  is  also  composed  to  a  large  extent  of  red  and  gray  feldspathic  granite,  with  the 
fossiliferous  rocks  inclining  high  upon  its  sides.  After  passing  the  sources  of  Wind 
River  the  mountains  appear  to  be  composed  entirely  of  eruptive  rocks.  Even  the  ' 
Three  Tetons,  which  raise  their  summits  11,000  feet  above  the  ocean  level,  are  formed 
of  very  compact  basaltic  rock.*  The  Wasatch  and  Green  River  Ranges,  where  we  ob- 
served them,  have  the  same  igneous  origin,  and  the  mountains  all  along  the  sources 
of  the  different  branches  of  the  Columbia  exhibit  these  rocks  in  their  full  force.  In 
Pierre's  Hole,  Jackson's  Hole,  and  other  valleys  surrounded  by  upheaved  ridges,  these 
ancient  volcanic  rocks  seem  to  have  been  poured  out  over  the  country  and  to  have 
cooled  in  layers,  giving  to  vast  thicknesses  of  the  rocks  the  appearance  of  stratified  beds. 

The  mountains  about  the  sources  of  the  Missouri  and  Yellowstone  Rivers  are  of  erup- 
tive origin,  and  in  the  valley  of  the  Madison  Fork  of  the  Missouri  are  vertical  walls  of 
these  ancient  volcanic  rocks  1,000  to  1,500  feet  in  height,  exhibiting  the  appearance 
of  regularly  stratified  deposits,  dipping  at  a  considerable  angle.  As  we  pass  down  the 
Madison  we  find  some  beds  of  feldspathic  rocks  and  mica  and  clay  slates  beneath  the 
eruptive  layers,  dipping  at  the  same  angle.  After  passing  the  divide  below  the  three 
forks  of  the  Missouri  we  see  a  number  of  partially  detached  ranges  which  appear  to  be 
of  the  same  igneous  character.  In  the  Belt  and  Highwood  Mountains,  and  indeed  all 
along  the  eastern  slope  in  this  region,  we  find  continual  evidence  of  the  outpouring  of 
the  fluid  material  in  the  form  of  surface  beds,  or  in  layers  thrust  between  the  fossilif- 
erous strata.  These  igneous  beds  thin  out  rapidly  as  we  recede  from  the  point  of  effu- 
sion. A  large  number  of  these  centers  of  protrusion  may  be  seen  along  the  slope  of 
the  mountains  west  of  the  Judith  Range.  The  erupted  material  sometimes  presents 
a  vertical  wall  300  feet  high,  then  suddenly  thins  out  and  disappears.  The  Judith, 
Bear's  Paw,  and  Little  Rocky  Mountains  seemed  to  be  composed  for  the  most  part  of 
granite  and  other  rocks,  with  igneous  protrusions  here  and  there.  I  have  in  a  former 
paper  expressed  the  opinion  that  the  central  portions  of  our  mountain  ranges  are  com- 
posed of  feldspathic  granite,  and  to  a  certain  extent  this  is  true  in  regard  to  the  more 
eastern  outliers,  but  more  recent  observations  have  convinced  me  that  these  rocks 
which  I  have  defined  by  the  term  " eruptive"  compose  by  far  the  greater  portion  01 
the  mountain  masses  of  the  West. 

-ROFT 

II. — POTSDAM   SANDSTONE   (SILURIAN).  ,/w; 

The  discovery  of  this  formation  in  its  western  extension  has  already  been  announced 
in  a  former  paper.t  It  was  first  made  known  as  occurring  in  the  Black  Hills  and  rest- 
ing upon  the  upturned  or  nearly  vertical  edges  of  the  schists,  clay  slates,  and  granit- 
oid rocks,  and  the  inference  was  drawn  that  the  same  rocks  would  be  found  forming  an 
outcropping  belt  along  the  eastern  slope  of  the  Rocky  Mountains.  After  leaving  the 
Black  Hills  we  next  observed  it  along  the  margins  of  the  Big  Horn  Range  near  the 
summit,  holding  the  same  relative  position  and  exhibiting  the  same  lithological  char- 
acters. A  few  thin  layers  of  fine  calcareous  sandstone  were  observed  filled  with  fossils 
characteristic  of  this  period.  At  the  head  of  La  Boiite  Creek,  in  the  Laramie  Range,  I 
noticed  a  bed  resting  discordantly  upon  Azoic  slates,  50  to  100  feet  in  thickness,  hold- 
ing the  same  position  and  possessing  the  same  lithological  characters  which  it  reveals 
at  other  localities.  I  could  discover  no  fossils  in  it  at  this  point,  but  I  am  confident 
that  this  bed  represents  the  Potsdam  sandstone.  The  same  bed  seems  to  occur  a 
along  the  mountains  from  Laramie  Peak  to  Cache  la  Poudre  Creek,  underlying  the  well- 
known  Carboniferous  strata,  and  resting  upon  the  decomposing  granitoid  rocks  wlm-h 
form  the  nucleus  of  the  first  ridge.  This  rock  (the  Potsdam)  is  more  or  less  changed 
by  heat  from  beneath,  but  I  was  able  to  trace  it  continuously  from  the  source  of  the 
Chuo-water  Creek  to  the  source  of  Cache  la  Poudre.  a  distance  of  over  II 
was  also  seen  along  the  eastern  slope  of  the  Wind  River  Mountains,  but  did  not  con- 
tain any  organic  remains. 

The  above  facts  show  very  clearly  that  in  its  western  extension,  the  primordial  zoi 
of  Barrande  is  represented  only  by  a  thin  bed  of  sandstone  never  exceeding  150  feet 
thickness,  and  that  it  is  seen  only  in  a  very  narrow  outcropping  belt  near  the  margins 
of  the  mountain  crests.     The  stratified  Azoic  rocks  upon  which  it  rests  discort  lai 1 1 1  \ .  s, i 
far  as  my  observations  have  extended,  never  reach  a  very  great  thickness 

*This  is  an  error.   The  Tetons  are  composed  mostly  of  gneissic  granite.     1878. 

tAm.  Jour.  Sci.  and  Arts,  vol.  xxvi,  276. 


972  REPORT    OF    THE    SECRETARY    OF    THE    INTERIOR. 

III. — CARBONIFEROUS  ROCKS  (INCLUDING  PERMIAN  ?). 

f  On  both  sides  of  the  divide  of  the  Rocky  Mountains,  so  far  as  our  explorations  have 
extended,  a  series  of  calcareous,  areno-calcareous,  and  arenaceous  beds  are  seen,  which 
we  have  referred  to  the  Carboniferous  epoch.  They  vary  in  thickness  at  different 
points.  Without  specifying  localities  it  will  be  sufficient  to  remark  that  all  along  the 
margins  of  any  of  the  mountain  elevations  in  the  far  West,  these  rocks  are  seen  in  a 
more  or  less  inclined  position. 

Sometimes  they  are  not  visible  for  a  short  distance  (as  between  the  Laramie  and 
Platte  Rivers,  20  or  30  miles),  but  it  is  plain  that  they  have  either  been  removed  by 
erosion  or  concealed  by  more  recent  deposits.  Along  the  Big  Horn  Mountains  there 
are  alternate  layers  of  sandstone,  arenaceous,  andmaguesian  limestones,  many  of  which 
show  oblique  laminae  and  other  indications  that  their  deposition  took  place  in  shallow 
and  perhaps  turbulent  waters.  They  are  here  developed  to  a  thickness  of  1,000  to 
1,500  feet,  and  incline  high  upon  the  sides  of  the  mountains  at  an  angle  of  50°  to  70°. 
They  contain  few  fossils,  but  these  indicate  rocks  of  the  same  age  as  those  in  the  Black 
Hills.  Along  the  Laramie  Mountains,  from  the  Red  Buttes  to  Pike's  Peak,  apparently 
the  same  limestones  are  see"n  inclining  against  the  sides  of  the  elevated  ridges  at  greater 
or  less  angles,  and  on  the  opposite  side  of  the  axis,  sloping  down  to  the  Laramie  Plains, 
the  corresponding  strata  are  seen,  though  leaning  at  much  smaller  angles,  usually 
from  9°  to  15°.  Along  the  Sweet  Water  and  Wind  River  Mountains  these  rocks  are 
highly  developed  and  incline  against  the  sides  of  the  ridges  of  elevation,  as  heretofore 
described.  The  corresponding  portions  are  also  seen  on  the  west  slope  of  the  main 
range  at  the  sources  of  Green  and  Snake  Rivers,  but  not  as  conspicuously  developed, 
the  eruptive  rocks  predominating.  Crossing  back  over  the  dividing  crest  near  the 
sources  of  the  Madison,  Jefferson,  and  Gallatin  Forks  of  the  Missouri,  we  find  similar 
limestones  largely  developed  and  covering  a  considerable  area  on  the  eastern  slope. 
Near  the  junction  of  the  three  forks  and  along  Smith's  or  Kainas  River  we  find  them 
reaching  a  thickness  of  800  to  1,000  feet,  often  partially  changed  by  contact  with  igne- 
ous rocks  beneath.  They  were  also  observed  around  the  Judith  Mountains,  and  also 
about  the  Bear's  Paw  and  Little  Rocky  Mountains. 

Nowhere  in  the  Rocky  Mountain  Range,  so  far  as  my  observations  have  extended,  do 
the  Carboniferous  rocks  seem  to  abound  in  organic  remains,  and  the  few  usually  seen 
are  generally  found  in  a  bad  state  of  preservation  and  comprise  a  limited  number  of 
species.  The  precise  period  to  which  these  rocks  belong  which  are  so  persistent  in  all 
disturbed  regions  is  not  positively  known,  the  evidence  from  organic  remains  pointing 
to  the  age  of  the  Coal  Measures  and  sometimes  to  that  of  the  Lower  Carboniferous  pe- 
riod; probably  both  members  of  the  system  occur  there. 

At  the  foot  of  the  Big  Horn  Mountains,  near  the  head  of  Powder  River,  I  observed 
at  one  locality  a  series  of  beds  which  indicated  the  presence  of  Permian  rocks.  These 
beds,  which  are  composed  of  cherty  magnesian  limestone,  are  very  much  like  those 
already  described  in  Northeastern  Kansas,  and  contain  in  great  abundance  some  of 
the  same  species  of  fossils  as  Myalina  perattenuata  and  others.  I  have  also  seen  similar 
limestones  in  other  localities,  out  no  fossils  were  detected,  and  though  having  a  Per- 
mian appearance  they  may  belong  to  the  upper  portion  of  the  Carboniferous. 

The  evidence  is  clear  in  many  localities  that  prior  to  the  deposition  of  the  Red  Marls 
succeeding  the  supposed  Permian  a  very  great  erosion  of  the  surface  of  the  Carbonif- 
erous rocks  took  place.  We  find,  for  example,  in  many  localities  only  a  thin  repre- 
sentation of  the  Carboniferous  rocks,  and  again  a  full  development,  1,000  to  1,500  feet 
in  thickness. 

IV. — RED  ARENACEOUS  DEPOSITS. 

Overlying  the  Carboniferous  rocks,  and  equally  persistent  with  them,  is  a  series  of 
red  arenaceous  marl  beds  or  gypsum-bearing  marls,  which  are  coextensive  with  the 
upheaved  sedimentary  formations  along  the  Rocky  Mountains.  The  largest  develop- 
ment of  these  beds  which  I  have  observed  occurs  on  the  northeastern  side  of  the  Big 
Horn  Mountains  and  on  the  west  slope  of  the  Wind  River  Mountains,  near  the  source 
of  the  Gros  Ventres  Fork  of  Snake  River.  From  the  Red  Buttes,  on  the  North  Platte, 
to  Pike's  Peak  these  beds  are  often  removed  by  erosion  or  concealed  by  superficial  de- 
posits, but  their  appearance  in  numerous  places  shoAvs  very  clearly  that  beneath  the 
surface  they  occupy  a  considerable  area  throughout  the  country  bordering  the  mount- 
ain ranges,  possibly  extending  entirely  over  the  eastern  slope.  Passing  over  into  the 
Laramie  Plains  we  find  that  the  red  marls  constitute  the  surface  formation  of  the  plain 
country.  It  has  also  been  shown  from  Mr.  H.  Engelinann's  explorations  that  these 
beds  are  revealed  along  the  Wasatch  Mountains,  even  south  of  Lake  Utah,  furnishing 
undoubted  evidence  that  they  belong  to  the  same  great  deposit.  The  fact  also  that 
1,000  to  1,500  feet  of  red  arenaceous  beds  are  seen  near  the  sources  of  Green  River, 
leads  to  the  inference  that  they  continue  southward  far  down  the  Green  River  Valley 
to  that  portion  which  takes  the  name  of  Colorado,  and  are  in  fact  a  continuation  of 
the  extensive  red  deposits  described  by  various  explorers  in  New  Mexico. 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       973 

These  red  beds  are  also  seen  under  similar  circumstances  highly  developed  alone  the 
mountains  at  the  sources  of  the  Missouri.  There  seems  to  be  a  change  in  the  Htho- 
logical  characters  below  the  Gate  of  the  mountains,  the  peculiar  red  deposits  disap- 
pearing for  the  most  part,  and  a  series  of  irregular'  layers  of  siliceous  limestone  with  a 
reddish  tinge,  and  with  oblique  laminse,  ripple-mark  and  other  indications  of  shallow- 
water  deposition.  It  is  through  these  layers  of  rock  that  the  Missouri  River  cuts  its 
way  from  the  foot  of  the  mountains  to  the  mouth  of  High  Wood  Creek,  about  10  miles 
below  the  falls.  They  are  also  distinctly  revealed  around  the  Judith  Mountains 
Along  the  Big  Horn  Mountains  thick  layers  of  gypsum  occur,  but  the  gypsum  beds 
are  by  no  means  coextensive  with  the  red  deposits,  and  indeed  are  present  in  but  few 
localities.  Near  the  head  of  Powder  River  the  aggregate  thickness  of  the  °ypsum 
strata  is  about  100  feet,  while  near  the  source  of  Snake  River  there  is  a  thickness  from 
50  to  80  feet.  It  also  occurs  to  a  considerable  extent  at  the  foot  of  the  mountains  on 
La  Bonte  Creek,  a  branch  of  the  North  Platte. 

V. — JURASSIC  ROCKS. 

These  rocks  are  everywhere  revealed,  overlying  the  red  deposits  just  mentioned  and 
possessing  an  equal  geographical  extension.  Their  fullest  development  and  most  fos- 
siliferous  condition  seems  to  be  along  the  margins  of  the  Black  Hills,  where  they  have 
furnished  the  most  satisfactory  evidence  of  their  age.  Along  the  northeastern  slope 
of  the  Big  Horn  Mountains  this  group  of  rocks  presents  its  usual  appearance  of  gray 
and  whitish  calcareous  and  arenaceous  layers,  with  indurated,  somewhat  variegated 
beds  of  more  or  less  laminated  marls,  containing  in  great  abundance  Belemnites  densus, 
Pentavrlnus  asteriscus,  a  new  species  of  Ostrea,  Pecten,  &c. 

At  Red  Buttes  we  find  a  fair  development  of  these  beds  with  the  same  fossils,  but  as 
we  proceed  southward  toward  Long's  Peak,  the  intercalated  laminated  marls  disap- 
pear and  the  whole  formation  seems  to  be  reduced  to  a  thickness  of  50  to  100  feet,  with 
very  few  fossils.  Along  the  southwest  side  of  the  Big  Horn  Mountains  and  the  north- 
east side  of  the  Wind  River  Mountains  we  have  a  thickness  of  Jurassic  rocks  from  800 
to  1,000  feet  containing  organic  remains  in  the  greatest  abundance.  Crossing  the  Wind 
River  Mountains  we  observed  the  strata  corresponding  to  those  upon  the  eastern  side, 
with  B.  densus,  Ostrea,  &c.  Returning  to  the  eastern  slope  at  the  sources  of  the  Mis- 
souri, we  see  occasional  indications  of  their  existence,  but  not  so  conspicuous  as  to  be 
readily  identified.  The  age  of  this  group  of  rocks  may  be  now  considered  as  thoroughly 
established,  so  great  a  number  of  fossils  which  appear  to  be  of  undoubted  Jurassic 
forms  having  been  obtained. 

I  have  remarked  that  the  older  fossiliferous  beds  doubtless  pass  beneath  the  more  re- 
cent Cretaceous  and  Tertiary  deposits,  and  occupy  a  greater  or  less  area  underneath 
the  prairie  country  east  of  the  "divide"  of  the  Rocky  Mountains.  I  have  made  this 
inference  from  the  fact  that  where  any  elevations  occur  the  complete  series  of  fossilif- 
erous beds  are  exposed  around  the  axis  of  upheaval.  That  I  may  not  be  misunderstood 
by  those  geologists  who  have  colored  large  areas  Triassic  and  Jurassic  on  geological 
maps  of  the  West,  I  would  say  that  I  liave  never  seen  any  of  the  older  fossiliferous 
rocks,  from  the  Potsdam  to  the  Jurassic,  inclusive,  exposed  except  in  narrow  outcrop- 
ping belts  around  the  margins  of  the  mountain  elevations.  The  Carboniferous  rocks 
occupy  a  belt  from  one  to  two  miles  wide,  and  the  red  arenaceous  deposits  are  exposed 
over  about  the  same  area,  while  the  Jurassic  form  a  zone  never  more  than  one-fourth 
of  a  mile  to  three  miles  in  width. 

VI. — CRETACEOUS  ROCKS  WITH  SUBDIVISIONS.* 

The  various  subdivisions  of  the  Cretaceous  Group  in  the  West  were  observed  at  nu- 
merous localities.  The  strata  in  many  places  occupy  large  geographical  areas,  holding 
a  horizontal  position,  in  others  forming  a  belt  or  zone  of  greater  or  less  width  around 
the  mountain  elevations.  No.  1  is  a  well-marked  and  distinct  division  along  the  Mis- 
souri River  from  De  Soto  to  a  point  above  the  mouth  of  the  Big  Sioux  River  in  the 
eastern  portions  of  Kansas  and  Nebraska  and  in  the  South  and  Southwest.  But  when 
we  come  into  the  vicinity  of  the  mountain  ranges  in  the  Northwest  its  typical  form  is 
wanting,  and  apparently  an  increased  development  of  No.  2  only  is  seen.  Along  the 
Big  Horn  Mountains,  No.  2  is  800  to  1,000  feet  in  thickness,  composed  of  black,  plastic 
clay  with  several  layers  of  gray  and  yellowish  calcareous  sandstones  10  to  50  feet  in 
thickness.  Along  the  Laramie  and  Wind  River  Mountains  the  same  characters  are 
shown.  After  leaving  the  Missouri,  near  the  mouth  of  the  Niobrara  River,  No.  3  is 
never  seen  presenting  its  typical  marly  character.  In  the  vicinity  of  the  Black  Hills 
we  saw  a  series  of  beds  composed  of  alternate  thin  layers  of  arenaceous  and  argilla- 

*  The  Cretaceous  rocks  of  the  West  have  been  divided  into  five  formations,  num- 
bered 1,  2,  3,  &c.  A  more  careful  study  of  No.  1  ?  may  render  it  necessary  to  make 
other  divisions. 


974     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

ceous  sediments  with  Ostrea  congesta  and  Inoceramus  problematicns  which  may  possibly 
represent  No.  3.  Along  the  Big  Horn  Mountains  and  from  Red  Biittes  to  Cache  la 
Poudre  Creek  the  same  fossils  were  pften  found  and  some  other  indications  of  its  ex- 
istence, but  no  well-marked  typical  beds  were  seen.  It  is  now  well  known  that  O. 
congesta  and  I.  problematicus  range  down  into  No.  2,  so  that  No.  3  in  the  West  and 
Southwest  may  give  place  to  an  increased  development  of  No.  2.  Nos.  4  and  5  are 
largely  developed  everywhere,  when  not  concealed  by  the  overlying  Tertiary  deposits, 
especially  along  the  Laramie  Mountains  and  in  the  valley  of  Cache  la  Poudre.  In  the 
valley  of  Wind  River  all  the  Cretaceous  rocks  down  to  No.  2  appear  to  have  been  re- 
moved by  erosion  prior  to  the  deposition  of  the  Tertiary  beds,  and  the  characteristic 
fossils  of  No.  2  are  quite  abundant.  As  we  pass  over  the  mountains,  we  have,  inclining 
from  the  western  slope,  600  to  800  feet  of  alternations  of  black  plastic  clays,  arenace- 
ous marls,  and  beds  of  sandstones  and  limestones,  with  a  few  seams  of  carbonaceous 
matter  passing  up  into  calcareous  and  arenaceous  compact  rocks.  In  some  arenace- 
ous limestones  near  the  middle  of  the  series,  and  extending  upward,  quite  abundant 
fossils  were  observed,  among  them  a  large  Inoceramus,  two  species  of  Oslrea,  a  large 
Pinna,  four  inches  in  length,  a  Cardium,  and  a  number  of  undetermined  species, 
with  fragments  of  silicified  wood.  The  general  dip  of  these  rocks  is  about  20°. 
These  well-marked  Cretaceous  beds  pass  up  quite  imperceptibly  into  an  enormous 
thickness  of  Lignite  Tertiary.  Passing  over  the  dividing  crest  to  the  headwaters 
of  the  Missouri,  we  did  not  observe  any  indications  of  Cretaceous  rocks  until  we  had 
descended  below  the  three  forks,  where  we  find  traces  left  after  erosion.  They  do  not 
reveal  themselves  conspicuously  until  we  arrive  within  twenty  or  thirty  miles  of  Fort 
Benton,  where  the  black,  plastic  clay  begins  to  overlap  the  Jurassic  rocks,  with  its 
characteristic  fossils,  and  on  reaching  Fort  Benton  the  plastic  clay  is  quite  homogeneous, 
and  is  developed  to  a  thickness  of  800  feet.  As  we  proceed  toward  the  mouth  of 
the  Judith  River  and  near  the  Judith  Mountains,  we  find  quite  thick  beds  of  concre- 
tionary sandstone  which  form  the  " Stone  Walls,"  "Citadel,"  &c.  It  is  from  these 
beds  that  we  have  obtained  a  group  of  fossils  which 'we  have  referred  provisionally  to 
No.  1,  but  which  seem  to  be  specifically  distinct  from  all  others  in  the  West.  It  may 
be  that  when  this  group  of  beds  now  referred  to  Nos.  1  and  2,  comprising  a  thickness 
of  1,500  to  2,000  feet  in  this  region,  are  more  carefully  studied,  that  several  subdivisions 
will  be  made,  having  equal  importance  with  the  others.  During  the  past  season  our 
route  led  us  along  the  "divide"  between  the  Missouri  and  Yellowstone  rivers,  south  of 
the  Judith  Mountains,  so  that  we  passed  outside  of  any  good  exposures  of  No.  1,  as  well 
as  beyond  the  limits  of  the  estuary  beds  at  the  mouth  of  the  Judith.  We  must  await  a 
more  thorough  and  detailed  exploration  of  this  region  before  we  can  state  with  entire 
confidence  the  succession  of  the  beds. 

VII. — TERTIARY   DEPOSITS. 

In  speaking  of  the  Tertiary  deposits  of  the  Northwest,  so  far  as  known  at;  the  present  • 
time,  I  propose  to  separate  them  into  four  divisions,  which  will  be  sufficient  for  our 
immediate  purposes :  1st.  Estuary  deposits.     2d.  True  Lignite  beds.     3d.  Wind  River 
Valley  deposits.     4th.  White  River  Tertiary  deposits. 

The  estuary  deposits,  of  which  the  Judith  Basin  may  be  regarded  as  the  type,  are 
quite  remarkable  and  of  a  most  interesting  character.  '  Opinions  of  a  somewhat  con- 
flicting nature  have  been  entertained  in  regard  to  them,  owing  to  the  peculiar  character 
of  the  organic  remains ;  but  recent  observations  have  convinced  me  that  they  are  all 
of  Tertiary  age,  and  that  they  are  quite  widely  distributed  throughout  the  for  West. 
The  lithological  characters  of  the  Judith  deposit  have  already  been  sufficiently  de- 
scribed, and  it  has  yielded  many  important  fossils.  A  thin  series  of  beds  is  also  found 
near  the  sources  of  the  Moreau,  Grand,  and  Cannon  Ball  Rivers;  and  at  the  mouth  of 
the  Big  Horn  River  we  have  a  group  of  beds  800  to  1,000  feet  in  thickness,  with  fossils 
of  the  same  character  as  those  occurring  at  the  mouth  of  the  Judith.  The  researches 
of  Mr.  H.  Engelrnann,  in  Utah,  have  also  established  the  existence  of  an  estuary  de- 
posit in  the  country  bordering  upon  Green  River,  scarcely  less  interesting  than  that  of 
the  Judith.  These  deposits  pass  up  into  the  true  lignite  beds  without  any  perceptible 
line  of  separation,  gradually  losing  their  estuary  character  and  ever  after  containing 
only  land  and  fresh-water  shells.  The  lignite  strata  are  chiefly  remarkable  for  yielding 
in  the  greatest  abundance  finely  preserved  vegetable  remains.  A  few  fragments  of 
leaves  of  Dicotyledonous  trees  and  silicified  wood,  with  very  impure  lignite  beds,  are 
formed  in  some  of  the  estuary  deposits,  but  no  groups  to  indicate  the  great  luxuriance 
of  vegetation  which  must  have  existed  during  the  accumulation  of  the  lignite  strata. 

The  geographical  extension  of  the  lignite  deposits  of  the  West  is  now  a  matter  of  the 
highest  interest,  and,  from  what  is  already  known,  I  am  convinced  that  they  will  yet 
be  found  to  cover  a  greater  or  less  area  on  both  sides  of  the  main  "divide"  of  the  Rocky 
Mountains,  from  the  Arctic  Sea  to  the  Isthmus  of  Darien.  The  estuary  and  lignite 
beds  seem  also  to  have  partaken  equally  with  the  older  fossiliferous  rocks  of  the  influ- 
ence which  elevated  the  mountain  chains.  Along  the  Laramie  Mountains  and  from 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.     •  975 

the  Red  Buttes  to  the  "divide"  between  Platte  and  Wind  Rivers,  along  the  Big  Horn 
Mountains,  the  strata  incline  at  very  high  angles,  40°  to  80°,  and  in  some  instances  are 
very  nearly  vertical.  The  true  lignite  strata  seem  to  conform  to  the  older  fossiliferous 
rocks  and  to  have  been  disturbed  by  the  same  influences  that  elevated  the  mountain 
ranges  in  the  vicinity.  These  Tertiary  beds  extended  over  all  the  plain  country  to  the 
north,  and  east  of  the  Laramie  Mountains,  far  to  the  northward,  beyond  the  limits  of 
our  explorations.  Crossing  the  Wind  River  Mountains,  we  find  them  largely  developed 
high  upon  the  western  slope,  dipping  at  a  high  angle,  from  the  Wind  River  Range  on 
the  one  side  and  the  Wasatch  and  Green  River  Mountains  on  the  other. 

Throughout  the  Wind  River  Valley  is  a  series  of  beds,  of  great  thickness,  which  seem 
to  be  intermediate  in  their  character  between  the  true  lignite  beds  and  the  White 
River  Tertiary  deposits.  We  first  observed  them  gently  inclined  near  Willow  Springs 
on  the  North  Platte,  and  thence  westward  toward  the  Sweet  Water  Mountains  and 
near  the  "divide"  between  the  North  Platte  and  Wind  River  they  reach  a  thickness  of 
400  feet.  From  this  "divide"  throughout  the  Wind  River  Valley  they  occupy  the 
greater  portion  of  the  country,  and,  though  inclining  in  the  same  direction  with  the 
older  strata,  the  beds  do  not  dip  more  than  1°  to  5°.  They  diifer  from  the  other  de- 
posits in  the  great  predominance  of  arenaceous  sediments  and  in  the  absence  of  vege- 
table remains,  but  they  contain  fragments  of  turtles  and  numerous  fresh-water  and 
land  shells  of  the  genera  Helix,  PlanorMs,  Vivipara,  &c.  The  entire  thickness  of  these 
deposits  may  be  estimated  at  from  1,500  to  2,000  feet.  From  the  fact  that  these  de- 
posits do  not  conform  to  the  true  lignite  beds  and  that  detached  portions  are  seen 
lying  upon  the  sides  of  the  mountains  but  slightly  inclined,  while  the  corresponding 
beds  are  shown  in  the  valley  below,  we  infer  that  they  were  accumulated  long  before 
the  mountains  were  raised  to  their  present  height,  or  perhaps  during  the  gradual  pro- 
cess of  elevation.  This  is  especially  shown  at  the  upper  end  of  the  Wind  River  Valley. 
Passing  over  the  Wind  River  Mountains  we  again  see  them  holding  the  same  position 
on  the  western  slope,  and  possessing  the  same  lithological  characters.  While  the  lig- 
nite beds  on  the  west  side  of  the  ''divide"  incline  at  a  large  angle,  the  more  recent 
beds,  although  in  some  places  occupying  the  very  crest  of  the  mountains,  seldom  in- 
cline more  than  3°  to  5°. 

The  most  interesting  additional  facts  which  we  have  obtained  in  regard  to  the 
White  River  Tertiary  beds,  are  their  geographical  extension  and  the  evidence  of  their 
age  in  relation  to  the  lignite  deposits.  We  can  now  show  beyond  a  doubt  that  the 
former  must  have  been  accumulated  long  since  the  latter.  We  have  ascertained  that 
they  extend  southward  along  the  Laramie  Mountains  to  Willow  Springs  within  10 
miles  of  Cache  la  Poudre ;  that  they  also  extend  up  the  North  Platte  to  the  Box  Elder 
Creek,  and  even  beyond  are  small  outliers,  showing  that  much  has  been  removed  by 
erosion.  Passing  over  into  the  Laramie  Plains  we  find  at  the  source  of  the  Box  Elder 
and  extending  over  to  the  head  of  Bates  Fork  a  large  development  of  this  Tertiary, 
and  it  also  reaches  far  westward  to  the  Medicine  Bow  Mountains.  We  also  know 
from  the  observations  of  Dr.  Hiues  that  it  occupies  a  considerable  area  among  the 
Sweet  Water  Mountains,  extending  over  into  the  Green  River  Valley.  We  have  along 
the  North  Platte  the  overlapping  of  the  White  River  beds  upon  the  lignite  strata,  thus 
affording  the  evidence  of '  superposition  for  their  relative  age.  The  same  fact  was  no- 
ticed between  the  North  Fork  of  the  Cheyenne  and  the  head  of  Cherry  Creek,  where 
beds  of  marl  and  limestone  containing  PlanorMs,  Limnea,  &c.,  the  same  as  are  seen  in 
the  Bad  Lands  proper,  repose  upon  true  lignite  Tertiary  strata.  Again,  while  the 
White  River  beds  hold  for  the  the  most  part  a  horizontal  position,  those  of  the  lignite 
Tertiary  are  often  much  disturbed.  Near  the  Black  Hills  the  former  seem  to  have  been 
elevated  to  a  considerable  height  by  'the  upheaval  of  the  mountains,  but  they  do  not 
in  any  case  incline  more  than  1°,  while  north  of  the  Black  Hills  the  lignite  beds  dip 
5°  to  10°.  Alono-  the  Platte  I  have  seen  the  former  inclining  5°,  especially  on  La 
Bonte  Creek  and  about  15  miles  east  of  the  mouth  of  that  creek.  Often  the  beds  seem 
to  have  been  raised  up  several  hundred  feet  above  their  original  position,  without 
inclination,  resting  upon  the  upturned  edges  of  the  lignite  beds  which  we  have  before 
observed,  partook -equally  of  the  disturbing  influences  which  have  given  so  gn-at  :m 
inclination  to  the  older  fossiliferous  rocks.  Along  the  Big  Horn  Mountains  and  tin- 
North  Platte  the  lignite  beds  sometimes  incline  from  the  foot  of  the  mountains  80-  .and 
often  the  influence  of  the  elevatory  power  has  affected  them  far  out  into 

C°In  the  above  accounts  of  the  Tertiary  deposits  of  the  West  we  have  shown  that  the 
older  members  are  clearly  separated  into  four  divisions  exclusive  bf  the  Pliocene  de- 
posits of  the  Niobrara.     Let  us  examine  the  evidence  in  regard  to  the  age  of  the* 
deposits.     If  we  study  the  upper  portions  of  Cretaceous  ionnnti on  >».  5  when  not 
removed  by  the  erosive  power  of  water  to  any  great  extent,  w.'  il..-i.  oWrvr  t,,m 
time  we  pass  from  No.  4  to  No.  5  a  gradual  change  in  the  sedn.H-n is   and  ml.,.    Ladiea- 
tions  of  a  slow  approach  to  shallow  water;  arenaceous  sediments  begin 
place  of  argillaceous,  so  that  we  have  alternate  thin  layers  01  sand  ™**™ 
continuing  to  increase  until  the  upper  part  becomes  a  yellow  im-n^mous, 


976     REPORT  OF  THE  SECRETARY  OF  THE  INTERIOR. 

stone,  with  most  conspicuous  examples  of  ripple-mark  and  oblique  laminae.  As  the 
waters  of  the  Cretaceous  sea  were  gradually  receding,  toward  the  Atlantic,  on  the  one 
side,  and  toward  the  Pacific  on  the  other,  remnants  were  left  in  the  form  of  lakes,  estu- 
aries, &c.,  which  now  afford  us  the  last  indications  of  marine  and  brackish  water 
deposits  in  the  central  portions  of  the  West.  In  these  deposits  we  have  first  a  ming- 
ling of  brackish  and  fresh  water  forms,  gradually  passing  up  to  pure  fresh  water  and 
terrestrial  species,  with  no  return  to  the  marine  condition  again. 

In  the  upper  part  of  the  Cretaceous  formation  No.  5,  on  the  Moreau,  we  find  the 
Ostrea  suUrigonalis,  and  in  the  Judith  deposits  a  form  occurs  in  the  greatest  abundance, 
which  is  undistiuguishable  from  it. 

'We  have  also  mentioned  the  fact  that  the  fossils  of  upper  part  of  No.  5  seem  to  have 
existed  upon  the  verge  of  the  Tertiary  period,  that  they  sometimes  present  peculiar 
forms  more  closely  allied  to  Tertiary  types  than  Cretaceous,  and  were  it  not  for  the 
presence  of  the  genera  Baculites,  Ammonites,  Inoceramus,  &c.,  which  are  everywhere 
supposed  to  have  become  extinct  at  the  close  of  the  Cretaceous  epoch,  we  would  be  in 
doubt  whether  to  pronounce  them  Tertiary  or  Cretaceous.  These  facts  would  seem  to 
indicate  a  foreshadowing  of  the  Tertiary  era,  and  that  the  transition  from  one  great 
period  to  the  other  Avas  gradual  and  quiet,  the  change  in  the  physical  conditions  being 
ultimately  sufficient  to  destroy  the  Cretaceous  fauna,  and  bring  into  existence  that  of 
the  Tertiary.  Again,  in  numerous  localities  where  No.  5  is  fully  developed  and  a  large 
thickness  of  Tertiary  deposits  is  superimposed,  so  that  near  some  of  the  mountain 
elevations  I  have  found  it  difficult  to  draw  the  line  of  separation,  no  apparent  physical 
break  occuring  in  the  sediments. 

Will  not  these  statements  go  far  to  show  that  the  estuary  deposits  ushered  in  the 
dawn  of  the  Tertiary  epoch  and  induce  the  belief  that  they  belong  to  the  first  part  or 
Eocene  period  ?  This  point  is  an  important  one  to  establish,  on  account  of  its  bearing 
upon  the  history  of  the  physical  development  of  our  western  continent. 

The  estuary  deposits  soon  lose  their  marine  and  brackish  character  and  gradually 
pass  up  into  the  true  lignite  strata,  of  purely  fresh-water  origin,  thence  by  a  slight 
discordancy  into  the  Wind  River  Valley  beds,  which  give  evidence  of  an  intermediate 
deposit  between  the  true  lignite  and  White  River  Tertiary  beds.  Then  come  the  White 
River  bone  beds,  which  pass  up  into  the  Pliocene  of  the  Niobrara  by  a  slight  physical 
break,  and  the  latter  are  lost  in  the  Yellow  Marl  or  Loess  deposits.  I  have  estimated 
the  entire  thickness  of  Tertiary  rocks  in  the  Northwest  at  from  5,000  to  6,000  feet,  and 
their  interest  will  be  appreciated  when  I  venture  to  suggest  that  by  thorough  investi- 
gation they  will  doubtless  reveal  in  a  most  remarkably  clear  manner  the  history  of  the 
physical  growth  and  development,  step  by  step,  of  the  central  portion  of  this  continent. 
I  shall  treat  this  subject  more  fully  in  a  future  paper,  and  would  refer  to  the  forth- 
coming report  of  Captain  Raynolds  for  the  details  of  the  facts  sustaining  my  opinions. 

We  have  no  evidence,  so  far  as  I  know,  of  long  continued  deep-water  deposits  in  the 
West,  until  far  up  in  the  Cretaceous  period.  If  we  examine  the  Potsdam  sandstone 
we  shall  find  that  where  it  reaches  its  greatest  force  the  lower  portion  is  composed  of 
an  aggregation  of  quartz  pebbles  cemented  with  siliceous  matter,  and  as  we  pass  up- 
ward, we  find  it  arranged  in  thin  layers  quite  compact  with  fucoidal  markings,  ripple- 
mark,  &c.  Everywhere  are  most  abundant  examples  of  oblique  laminae  of  deposition 
and  ripple  and  wave  markings — evidences  of  shallow  waters. 

During  the  long  period  that  elapsed  between  the  deposition  of  the  earliest  part  of 
the  Silurian  epoch  and  the  commencement  of  the  Carboniferous  we  have  reason  to  be- 
lieve that  dry  land  prevailed  over  a  large  portion  of  the  West.  The  Carboniferous 
epoch  commences  with  thin  layers  of  arenaceous  deposits,  gradually  passing  up  into 
homogeneous  siliceous  and  calcareous  beds.  The  latter  are  never  more  than  from 
20  to  50  feet  in  thickness,  and  then  the  arenaceous  sediments  begin  again  to  predomi- 
nate, and  all  the  proofs  of  shallow  as  well  as  turbulent  waters  are  shown.  We  then 
pass  up  through  the  red  arenaceous  deposits  and  Jurassic  beds,  and  find  no  rocks  that 
indicate  deep  water  deposition.  Cretaceous  formation  No.  1  commences  in  many  places 
with  a  considerable  thickness  of  an  aggregation  of  water-worn  pebbles  passing  up  into 
thin  alternate  layers  of  arenaceous  and  argillaceous  sediments  with  thick  beds  of  sand- 
stone with  ripple  markings  and  oblique  laminae,  then  gradually  ceases  in  No.  2,  and 
through  Nos.  2,  3,  and  4,  the  sediments  indicate  that  they  were  accumulated  in  com- 
paratively deep  and  quiet  waters.  No.  2  is  a  black  plastic  clay,  No.  3,  gray  marl,  and 
No.  4,  a  dark  indurated,  sometimes  laminated,  clay,  with  many  calcareous  concretions. 
In  No.  5  we  gradually  approach  indications  of  shallow  Avater  until  dry  land  appears,  as 
already  stated. 

It  will  not  be  possible  at  this  time  to  mention  in  detail  all  the  oscillations  of  surface 
and  other  physical  changes  to  which  Ave  have  reason  for  supposing  the  country  Avas. 
subjected  during  all  these  periods.  It  is  sufficient  for  our  present  purpose  to  show 
that,  except  during  the  Middle  Cretaceous  epoch,  no  long-continued  periods  of  quiet 
water  prevailed  in  these  ancient  western  seas. 

The  evidence  appears  to  me  to  point  to  the  conclusion  that  a  much  milder  climate 
prevailed  throughout  the  Avestern  portions  of  our  continent,  during  a  greater  part  of 


GEOLOGICAL  SURVEY  OF  THE  TERRITORIES.       977 

the  Tertiary  period,  than  that  which  exists  iii  the  same  latitudes  at  the  present  time. 
The  organic  remains  appear  to  indicate  a  subtropical  climate,  or  one  similar  to  that  of 
our  Gulf  States.  Near  the  close  of  the  Cretaceous  epoch  the  waters  of  the  great  Creta- 
ceous sea  receded  toward  the  present  position  of  the  Atlantic  011  the  one  side,  and  to- 
ward that  of  the  Pacific  on  the  other,  leaving  large  areas  in  the  central  portions  of  the 
West,  dry  land.  These  areas  were  of  course  in  close  proximity  to  the  sea,  and  com- 
paratively but  slightly  elevated  above  the  ocean  waters.  In  regard  to  the  mollusca 
which  have  been  found  quite  abundantly  entombed  in  the  lignite-bearing  strata,  it  is 
an  interesting  fact  that  the  most  nearly  allied  living  representatives  of  many  of  these 
species  are  now  found  inhabiting  the  streams  of  Southern  Africa,  Asia,  China,  and 
Siam,  apparently  indicating  the  existence  of  a  tropical  climate  in  these  latitudes  at 
as  late  a  period  as  the  Tertiary  epoch.* 

Again,  the  luxuriance  of  the  flora  which  has  been  so  perfectly  preserved  in  the  lig- 
nite strata  of  the  West  point  to  the  same  conclusion.  It  is  true  that  until  recently  no 
species  have  been  found  which  belong  exclusively  to  a  tropical  vegetation,  but  during 
our  last  expedition  we  obtained  a  species  of  true  fan-palm,  very  closely  allied  to  Sabal 
lamonis,  figured  by  Dr.  Heer  in  his  "  Flora  Tertiaria  Helvetia."  "  The  most  northern 
limit  of  palms  is  that  of  Chamcerops  palmetto,  in  North  America,  in  latitude  34°-36°,  and 
of  Chamcerops  humilis  in  Europe,  near  Nice,  in  43°-44°  N.  latitude."t  The  true  palms 
of  our  present  day  are  considered  as  having  their  native  laud  within  the  tropics.  That 
this  or  a  similar  condition  of  climate  continued  throughout  the  accumulation  of  the 
Wind  River  Valley  deposits  may  be  inferred  from  their  molluscau  remains,  which  are 
more  nearly  allied  to  tropical  forms. 

Again,  we  have  in  this  region,  as  before  mentioned,  an  extensive  area  occupied  by  the 
lignite-bearing  strata.  There  are  from  30  to  50  beds  of  lignite,  varying  in  thickness 
from  1  inch  to  7  feet.  Over  all  this  great  area  there  are  at  the  present  time  no  large 
forests,  no  timber  except  that  which  skirts  the  streams.  We  now  know  that  during  the 
Tertiary  period  vast  forests  of  timber  must  have  covered  many  portions  of  the  far  West 
from  the  abundance  and  variety  of  the  vegetable  remains  preserved  in  the  rocks.  Silici- 
fied  trunks  of  trees,  50  to  100  feet  in  length  and  2  to  4  feet  in  diameter,  and  stumps  which 
indicate  gigantic  forest  trees  occur  abundantly  over  hundreds  of  square  miles  along 
the  Missouri  and  Yellowstone  Rivers.  Professor  Henry  and  other  meteorologists  have 
arrived  at  the  conclusion,  from  a  vast  number  of  well-authenticated  facts,  that  the  ab- 
sence of  forest  trees  on  the  great  prairies  of  the  far  West  is  due  to  the  want  of  moisture, 
which  is  well  known  to  prevail  all  along  the  eastern  slope  of  the  Rocky  Mountains. 
The  prevailing  winds  are  now  known  to  come  from  the  west  and  northwest,  and,  as 
the  currents  of  air  laden  with  moisture  from  the  Pacific  ascend  the  western  slope  of 
the  mountains,  become  condensed  and  deposit  their  burdens  for  the  most  part  before 
reaching  the  eastern  slope. 

Professor  Henry,  in  his  paper  on  Climatology,  contributed  to  the  Patent  Office  Re- 
port for  1856,  says:  "The  return  westerly  current,  sweeping  over  the  Pacific  Ocean, 
and  consequently  charged  with  moisture,  will  impinge  on  the  Coast  Range  of  moun- 
tains of  Oregon  and  California,  and,  in  ascending  its  slopes,  deposit  moisture  on  Tli<> 
western  declivity,  giving  fertility  and  a  healthful  climate  to  a  narrow  strip  of  country 
bordering  on  the  ocean,  and  sterility  to  the  eastern  slope.  All  the  moisture,  however, 
will  not  be  deposited  in  the  passage  over  the  first  range,  but  a  portion  will  be  pre- 
cipitated on  the  western  side  of  the  next,  until  it  reaches  the  eastern  elevated  ridge  ot 
the  Rocky  Mountain  system,  when,  we  think,  it  will  be  nearly,  if  not  quite,  ex- 
hausted." We  are  now  supposing  that  the  climatic  conditions— winds,  currents  of  air, 
&c.,  did  not  differ  to  any  great  extent  during  the  Tertiary  epoch  from  those  which 
prevail  in  the  same  latitudes  at  the  present  day.  We  therefore  venture  the  suggestion 
that  up  to  the  time  of  the  accumulation  of  the  Middle  Tertiary  deposits  the  lofty 
barrier  of  the  Rocky  Mountains  did  not  exist. 

WASHINGTON,  D.  C.,  January  20,  1861.  

*  See  Memoir  by  F.  B.  Meek  and  F.  V.  Hayden  in  Proc.  Phila.  Acad.,  June,  1856. 
tLindley's  Vegetable  Kingdom,  p.  136. 
62  I 


